Solution Manual for Chemistry A Molecular Approach, 4th Edition
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INSTRUCTOR MANUAL
FOR
LABORATORY MANUAL
JOHN B. VINCENT
AND
ERICA LIVINGSTON
CHEMISTRY
A MOLECULAR APPROACH
Fourth Edition
NIVALDO J. TRO
FOR
LABORATORY MANUAL
JOHN B. VINCENT
AND
ERICA LIVINGSTON
CHEMISTRY
A MOLECULAR APPROACH
Fourth Edition
NIVALDO J. TRO
ii
Table of Contents
Experiment 1 Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion? 1
Experiment 2 Components of a Mixture – What Is That Stuff in the Bottom of the Cereal Box? 3
Experiment 3 Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number 5
Experiment 4 Conservation of Mass and Reaction Types – Copper Recovery Cycle 8
Experiment 5 Equivalent Weights and the Periodic Table 10
Experiment 6 Hydrates 12
Experiment 7 Gas Laws 14
Experiment 8 Styrofoam Cup Calorimetry: Atomic Weights 16
Experiment 9 Chemiluminescence: Glow Stick in a Beaker 19
Experiment 10 Atomic Spectra 22
Experiment 11 Reactivity of Group 1 Metals – Yes, Mom, I Threw Sodium in Water in Class
Today 23
Experiment 12 Flame Tests – Flames and Smoke Bombs 26
Experiment 13 VSEPR and Molecular Models 29
Experiment 14 Simulating the Shroud of Turin: An Inquiry-based Experiment 31
Experiment 15 Taste Observe the rainbow: Paper Chromatography 34
Experiment 15B Chemical Oil Dispersant Experiment 36
Experiment 16 Sublimation 41
Experiment 17 Closest Packed Structures 43
Experiment 18 Colligative Properties – Freezing Point Depression 47
Experiment 19A Diet Coke and Mentos – An Inquiry-Based Experiment 49
Experiment 19B Kinetics: Testing for Semen – Acid Phosphatase 51
Experiment 19C Activation Energy Determination 54
Experiment 20 Equilibrium Constants and LeChatelier’s Principle – CoCl2 56
Experiment 21 Far from Equilibrium Systems: Creating Life in a Beaker 61
Experiment 22 Acid-base Titration 63
Experiment 23 Determining the Buffer Capacity of Antacids 65
Experiment 24 Entropy – The Chelate Effect 67
Experiment 25 Redox Reactions – Detecting Traces of Blood 69
Experiment 26 Radioactivity 72
Experiment 27A Group I Cations 75
Experiment 27B Group II Cations: “I love the smell of hydrogen sulfide – It smells like victory” 77
Experiment 27C Piltdown Man and Scientific Ethics 80
Experiment 27D Group IV Cations 83
Experiment 27E Anions 85
Experiment 28 Esters 87
Experiment 29 Which Compounds Are Genotoxic or Carcinogens?: Cleaving Plasmid DNA and
Gel Electrophoresis
89
Table of Contents
Experiment 1 Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion? 1
Experiment 2 Components of a Mixture – What Is That Stuff in the Bottom of the Cereal Box? 3
Experiment 3 Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number 5
Experiment 4 Conservation of Mass and Reaction Types – Copper Recovery Cycle 8
Experiment 5 Equivalent Weights and the Periodic Table 10
Experiment 6 Hydrates 12
Experiment 7 Gas Laws 14
Experiment 8 Styrofoam Cup Calorimetry: Atomic Weights 16
Experiment 9 Chemiluminescence: Glow Stick in a Beaker 19
Experiment 10 Atomic Spectra 22
Experiment 11 Reactivity of Group 1 Metals – Yes, Mom, I Threw Sodium in Water in Class
Today 23
Experiment 12 Flame Tests – Flames and Smoke Bombs 26
Experiment 13 VSEPR and Molecular Models 29
Experiment 14 Simulating the Shroud of Turin: An Inquiry-based Experiment 31
Experiment 15 Taste Observe the rainbow: Paper Chromatography 34
Experiment 15B Chemical Oil Dispersant Experiment 36
Experiment 16 Sublimation 41
Experiment 17 Closest Packed Structures 43
Experiment 18 Colligative Properties – Freezing Point Depression 47
Experiment 19A Diet Coke and Mentos – An Inquiry-Based Experiment 49
Experiment 19B Kinetics: Testing for Semen – Acid Phosphatase 51
Experiment 19C Activation Energy Determination 54
Experiment 20 Equilibrium Constants and LeChatelier’s Principle – CoCl2 56
Experiment 21 Far from Equilibrium Systems: Creating Life in a Beaker 61
Experiment 22 Acid-base Titration 63
Experiment 23 Determining the Buffer Capacity of Antacids 65
Experiment 24 Entropy – The Chelate Effect 67
Experiment 25 Redox Reactions – Detecting Traces of Blood 69
Experiment 26 Radioactivity 72
Experiment 27A Group I Cations 75
Experiment 27B Group II Cations: “I love the smell of hydrogen sulfide – It smells like victory” 77
Experiment 27C Piltdown Man and Scientific Ethics 80
Experiment 27D Group IV Cations 83
Experiment 27E Anions 85
Experiment 28 Esters 87
Experiment 29 Which Compounds Are Genotoxic or Carcinogens?: Cleaving Plasmid DNA and
Gel Electrophoresis
89
ii
Table of Contents
Experiment 1 Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion? 1
Experiment 2 Components of a Mixture – What Is That Stuff in the Bottom of the Cereal Box? 3
Experiment 3 Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number 5
Experiment 4 Conservation of Mass and Reaction Types – Copper Recovery Cycle 8
Experiment 5 Equivalent Weights and the Periodic Table 10
Experiment 6 Hydrates 12
Experiment 7 Gas Laws 14
Experiment 8 Styrofoam Cup Calorimetry: Atomic Weights 16
Experiment 9 Chemiluminescence: Glow Stick in a Beaker 19
Experiment 10 Atomic Spectra 22
Experiment 11 Reactivity of Group 1 Metals – Yes, Mom, I Threw Sodium in Water in Class
Today 23
Experiment 12 Flame Tests – Flames and Smoke Bombs 26
Experiment 13 VSEPR and Molecular Models 29
Experiment 14 Simulating the Shroud of Turin: An Inquiry-based Experiment 31
Experiment 15 Taste Observe the rainbow: Paper Chromatography 34
Experiment 15B Chemical Oil Dispersant Experiment 36
Experiment 16 Sublimation 41
Experiment 17 Closest Packed Structures 43
Experiment 18 Colligative Properties – Freezing Point Depression 47
Experiment 19A Diet Coke and Mentos – An Inquiry-Based Experiment 49
Experiment 19B Kinetics: Testing for Semen – Acid Phosphatase 51
Experiment 19C Activation Energy Determination 54
Experiment 20 Equilibrium Constants and LeChatelier’s Principle – CoCl2 56
Experiment 21 Far from Equilibrium Systems: Creating Life in a Beaker 61
Experiment 22 Acid-base Titration 63
Experiment 23 Determining the Buffer Capacity of Antacids 65
Experiment 24 Entropy – The Chelate Effect 67
Experiment 25 Redox Reactions – Detecting Traces of Blood 69
Experiment 26 Radioactivity 72
Experiment 27A Group I Cations 75
Experiment 27B Group II Cations: “I love the smell of hydrogen sulfide – It smells like victory” 77
Experiment 27C Piltdown Man and Scientific Ethics 80
Experiment 27D Group IV Cations 83
Experiment 27E Anions 85
Experiment 28 Esters 87
Experiment 29 Which Compounds Are Genotoxic or Carcinogens?: Cleaving Plasmid DNA and
Gel Electrophoresis
89
Table of Contents
Experiment 1 Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion? 1
Experiment 2 Components of a Mixture – What Is That Stuff in the Bottom of the Cereal Box? 3
Experiment 3 Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number 5
Experiment 4 Conservation of Mass and Reaction Types – Copper Recovery Cycle 8
Experiment 5 Equivalent Weights and the Periodic Table 10
Experiment 6 Hydrates 12
Experiment 7 Gas Laws 14
Experiment 8 Styrofoam Cup Calorimetry: Atomic Weights 16
Experiment 9 Chemiluminescence: Glow Stick in a Beaker 19
Experiment 10 Atomic Spectra 22
Experiment 11 Reactivity of Group 1 Metals – Yes, Mom, I Threw Sodium in Water in Class
Today 23
Experiment 12 Flame Tests – Flames and Smoke Bombs 26
Experiment 13 VSEPR and Molecular Models 29
Experiment 14 Simulating the Shroud of Turin: An Inquiry-based Experiment 31
Experiment 15 Taste Observe the rainbow: Paper Chromatography 34
Experiment 15B Chemical Oil Dispersant Experiment 36
Experiment 16 Sublimation 41
Experiment 17 Closest Packed Structures 43
Experiment 18 Colligative Properties – Freezing Point Depression 47
Experiment 19A Diet Coke and Mentos – An Inquiry-Based Experiment 49
Experiment 19B Kinetics: Testing for Semen – Acid Phosphatase 51
Experiment 19C Activation Energy Determination 54
Experiment 20 Equilibrium Constants and LeChatelier’s Principle – CoCl2 56
Experiment 21 Far from Equilibrium Systems: Creating Life in a Beaker 61
Experiment 22 Acid-base Titration 63
Experiment 23 Determining the Buffer Capacity of Antacids 65
Experiment 24 Entropy – The Chelate Effect 67
Experiment 25 Redox Reactions – Detecting Traces of Blood 69
Experiment 26 Radioactivity 72
Experiment 27A Group I Cations 75
Experiment 27B Group II Cations: “I love the smell of hydrogen sulfide – It smells like victory” 77
Experiment 27C Piltdown Man and Scientific Ethics 80
Experiment 27D Group IV Cations 83
Experiment 27E Anions 85
Experiment 28 Esters 87
Experiment 29 Which Compounds Are Genotoxic or Carcinogens?: Cleaving Plasmid DNA and
Gel Electrophoresis
89
iii
Preface for Instructors
When one of the authors was in high school deciding what major he would be in college, he
was leaning toward chemistry. He favored chemistry over physics and mathematics because of what
he had performed in chemistry lab with his own hands. Somehow there was something more to
mixing the chemicals together and getting precipitates, gas bubbles, or color changes than watching a
block slide down an inclined plane. Getting into the lab and making something happen (i.e., blowing
something up) or making something new is probably the inspiration for nearly all budding chemists.
Chemistry is a “hands-on” science. How often do we say this to our students or to
administrators to justify the expense of the lab? Chemists inherently understand this to be true. Seeing
something happen is more educational and powerful than only discussing the theory behind it. At a
fundamental level, chemistry occurs beyond the naked eye, beyond the grasp of most of our senses.
One of the authors was fortunate in having an excellent laboratory experience in high school; he even
got to throw tiny pieces of sodium metal into a beaker, rapidly cover the beaker with a watch glass,
and observe what happens, for example. When he talks to old high school companions who went into
other areas, they still remember this experiment.
This is the kind of excitement we are aiming for in this laboratory manual project. We want
students to see things for themselves and do things for themselves that will emphasize the concepts
from the lecture portion of general chemistry. Most laboratory manuals seem to be a tired rehashing
of the same material – all but interchangeable. The authors often seem to forget to ask whether the
experiment would have been fun or exciting if they were a student. Thus, one finds dry “cookbook”
laboratory manuals. The “cookbook” label is somewhat unfair as no matter what type of laboratory
experiment is being performed (even an inquiry-based experiment), the students must be guided
through the exercise. A novice observer cannot be expected to necessarily make the important
observations without training into what is important to look for.
With this in mind, we are attempting to devise a laboratory manual that is concept oriented,
has varying levels of student guidance ranging from what is now called “inquiry-based” to classical
“cookbook” and hands-on and exciting. Why should the professor in front of the class be the only one
to perform the exciting chemistry of the lecture demonstrations? Why not have students throw sodium
into water, make things glow in the dark, and mix chemicals together to get results they never could
anticipate (as in an oscillating reaction)? We also believe that some issues not normally treated in the
laboratory to an appreciable degree can be covered such as the scientific method and scientific ethics.
All this can be handled, we believe, without straying too far from familiar territory to those
individuals who must be in the trenches setting up experiments, teaching the lab, or directing graduate
assistants. Thus, a variety of techniques to approach “traditional” experiments will be presented to
students. Some are open ended. Some are inquiry driven. Some are driven by attempting to obtain an
answer close to an accepted standard. Some are based on current events, some on current
“sensational” entertainment, and some on history. Through it all, our aim is to present concrete and
graspable theories with experiment and example.
We are including qualitative analysis in this manual. We believe the logic structure of this
process, including using flow diagrams, is an important contribution to the course.
Preface for Instructors
When one of the authors was in high school deciding what major he would be in college, he
was leaning toward chemistry. He favored chemistry over physics and mathematics because of what
he had performed in chemistry lab with his own hands. Somehow there was something more to
mixing the chemicals together and getting precipitates, gas bubbles, or color changes than watching a
block slide down an inclined plane. Getting into the lab and making something happen (i.e., blowing
something up) or making something new is probably the inspiration for nearly all budding chemists.
Chemistry is a “hands-on” science. How often do we say this to our students or to
administrators to justify the expense of the lab? Chemists inherently understand this to be true. Seeing
something happen is more educational and powerful than only discussing the theory behind it. At a
fundamental level, chemistry occurs beyond the naked eye, beyond the grasp of most of our senses.
One of the authors was fortunate in having an excellent laboratory experience in high school; he even
got to throw tiny pieces of sodium metal into a beaker, rapidly cover the beaker with a watch glass,
and observe what happens, for example. When he talks to old high school companions who went into
other areas, they still remember this experiment.
This is the kind of excitement we are aiming for in this laboratory manual project. We want
students to see things for themselves and do things for themselves that will emphasize the concepts
from the lecture portion of general chemistry. Most laboratory manuals seem to be a tired rehashing
of the same material – all but interchangeable. The authors often seem to forget to ask whether the
experiment would have been fun or exciting if they were a student. Thus, one finds dry “cookbook”
laboratory manuals. The “cookbook” label is somewhat unfair as no matter what type of laboratory
experiment is being performed (even an inquiry-based experiment), the students must be guided
through the exercise. A novice observer cannot be expected to necessarily make the important
observations without training into what is important to look for.
With this in mind, we are attempting to devise a laboratory manual that is concept oriented,
has varying levels of student guidance ranging from what is now called “inquiry-based” to classical
“cookbook” and hands-on and exciting. Why should the professor in front of the class be the only one
to perform the exciting chemistry of the lecture demonstrations? Why not have students throw sodium
into water, make things glow in the dark, and mix chemicals together to get results they never could
anticipate (as in an oscillating reaction)? We also believe that some issues not normally treated in the
laboratory to an appreciable degree can be covered such as the scientific method and scientific ethics.
All this can be handled, we believe, without straying too far from familiar territory to those
individuals who must be in the trenches setting up experiments, teaching the lab, or directing graduate
assistants. Thus, a variety of techniques to approach “traditional” experiments will be presented to
students. Some are open ended. Some are inquiry driven. Some are driven by attempting to obtain an
answer close to an accepted standard. Some are based on current events, some on current
“sensational” entertainment, and some on history. Through it all, our aim is to present concrete and
graspable theories with experiment and example.
We are including qualitative analysis in this manual. We believe the logic structure of this
process, including using flow diagrams, is an important contribution to the course.
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iv
When we set out to write this manual, our intention was to have detailed waste-disposal
procedures. As we looked into this issue, we found that local regulations and restrictions were so
varied as to make this impractical. We have made notes of when items require particular care,
regardless of location. Please work with your chemical hygiene officer to work out the proper
conditions for your location.
We hope you and your students can have fun and learn from what follows. In addition, please
feel free to send us your comments or those of your colleagues and students. We appreciate any input
so that we can continuously improve this manual.
John B. Vincent and Erica Livingston
When we set out to write this manual, our intention was to have detailed waste-disposal
procedures. As we looked into this issue, we found that local regulations and restrictions were so
varied as to make this impractical. We have made notes of when items require particular care,
regardless of location. Please work with your chemical hygiene officer to work out the proper
conditions for your location.
We hope you and your students can have fun and learn from what follows. In addition, please
feel free to send us your comments or those of your colleagues and students. We appreciate any input
so that we can continuously improve this manual.
John B. Vincent and Erica Livingston
Loading page 5...
v
General Laboratory and Safety Rules
For the Instructor
The general laboratory and safety rules are only intended to provide basics common to all general
chemistry laboratories; they are not meant to be comprehensive or to cover the specialized needs of
any particular laboratory situation and environment. Each instructor should provide details and edit
the rules as necessary to their own situation. Instructors should acquaint themselves with more
comprehensive laboratory safety publications such as Safety in Academic Chemistry Laboratories
published by the American Chemical Society.1
1. American Chemical Society Committee on Chemical Safety. Safety in Academic Chemistry
Laboratories, 7th ed. American Chemical Society: Washington, DC, 2003.
General Laboratory and Safety Rules
For the Instructor
The general laboratory and safety rules are only intended to provide basics common to all general
chemistry laboratories; they are not meant to be comprehensive or to cover the specialized needs of
any particular laboratory situation and environment. Each instructor should provide details and edit
the rules as necessary to their own situation. Instructors should acquaint themselves with more
comprehensive laboratory safety publications such as Safety in Academic Chemistry Laboratories
published by the American Chemical Society.1
1. American Chemical Society Committee on Chemical Safety. Safety in Academic Chemistry
Laboratories, 7th ed. American Chemical Society: Washington, DC, 2003.
Loading page 6...
vi
Name__________________________________________________ Student No:_______________________
Room & Day _____________________ Desk Number ________ Course & Section ____________________
Received Received
In From In From
Drawer Stockroom Price Drawer Stockroom Price
_____ _____ 1 Beaker, 50ml $3.23 _____ _____ 1 Litmus paper, red $0.77
_____ _____ 1 Beaker, 100ml $4.35 _____ _____ 1 Litmus paper, blue $0.77
_____ _____ 1 Beaker, 250ml $4.20 _____ _____ 1 Pipet, serological (measuring)
10ml
$10.60
_____ _____ 1 Beaker, 400ml $3.75 _____ _____ 6 Pipets, dropping, w/bulb $0.45
_____ _____ 1 Beaker, 600ml $6.18 _____ _____ 1 Spatula, scraper $9.10
_____ _____ 1 Bottle, Nalgene 250ml $1.73 _____ _____ 1 Sponge $1.84
_____ _____ 1 Bottle, Nalgene, 500ml $2.67 _____ _____ 6 Stirring rods, 6″ $1.66
_____ _____ 1 Bottle, wash, 250ml $4.14 _____ _____ 1 Stopper, #4, 1-hole, split $0.78
_____ _____ 1 Brush, test tube, 8″ $2.66 _____ _____ 1 Support, test tube $10.90
_____ _____ 1 Brush, test tube, 10 1/2″ $4.40 _____ _____ 12 Test tubes, 10mm × 75mm
(3″)
$0.44
_____ _____ 1 Bulb, 30ml, rubber $15.81 _____ _____ 6 Test tubes, 16mm × 150mm
(6″)
$0.63
_____ _____ 1 Clamp, pinch $4.58 _____ _____ 2 Test tubes, 25mm × 200mm
(8″)
$1.21
_____ _____ 1 Clamp, test tube $5.80 _____ _____ 1 Wire gauze, 6″ × 6″ ceramic $1.68
_____ _____ 1 Cylinder, graduated, 10ml $10.01 _____ _____ 1 Clay triangle $1.98
_____ _____ 1 Cylinder, graduated,
100ml
$16.03 _____ _____ 1 Tongs, nickel-plated $15.46
_____ _____ 1 Flask, Erlenmeyer,
125ml
$4.69 _____ _____ 2 Watch glasses, 50mm $4.05
_____ _____ 1 Flask, Erlenmeyer,
250ml
$4.69 _____ _____ 1 Stir bar $3.55
_____ _____ 1 Funnel, glass, 65mm lg $9.76 _____ _____ 1 Thermometer $17.51
Lost or broken items should be replaced promptly.
The above items were received in good condition, as verified by signature below. I understand that these items are
solely my responsibility and that I must return everything I receive, also in good condition.
Checked-in by____________________________________________Date checked-in__________________________
Student Signature
TA Signature _____________________________________________Date __________________________
Name__________________________________________________ Student No:_______________________
Room & Day _____________________ Desk Number ________ Course & Section ____________________
Received Received
In From In From
Drawer Stockroom Price Drawer Stockroom Price
_____ _____ 1 Beaker, 50ml $3.23 _____ _____ 1 Litmus paper, red $0.77
_____ _____ 1 Beaker, 100ml $4.35 _____ _____ 1 Litmus paper, blue $0.77
_____ _____ 1 Beaker, 250ml $4.20 _____ _____ 1 Pipet, serological (measuring)
10ml
$10.60
_____ _____ 1 Beaker, 400ml $3.75 _____ _____ 6 Pipets, dropping, w/bulb $0.45
_____ _____ 1 Beaker, 600ml $6.18 _____ _____ 1 Spatula, scraper $9.10
_____ _____ 1 Bottle, Nalgene 250ml $1.73 _____ _____ 1 Sponge $1.84
_____ _____ 1 Bottle, Nalgene, 500ml $2.67 _____ _____ 6 Stirring rods, 6″ $1.66
_____ _____ 1 Bottle, wash, 250ml $4.14 _____ _____ 1 Stopper, #4, 1-hole, split $0.78
_____ _____ 1 Brush, test tube, 8″ $2.66 _____ _____ 1 Support, test tube $10.90
_____ _____ 1 Brush, test tube, 10 1/2″ $4.40 _____ _____ 12 Test tubes, 10mm × 75mm
(3″)
$0.44
_____ _____ 1 Bulb, 30ml, rubber $15.81 _____ _____ 6 Test tubes, 16mm × 150mm
(6″)
$0.63
_____ _____ 1 Clamp, pinch $4.58 _____ _____ 2 Test tubes, 25mm × 200mm
(8″)
$1.21
_____ _____ 1 Clamp, test tube $5.80 _____ _____ 1 Wire gauze, 6″ × 6″ ceramic $1.68
_____ _____ 1 Cylinder, graduated, 10ml $10.01 _____ _____ 1 Clay triangle $1.98
_____ _____ 1 Cylinder, graduated,
100ml
$16.03 _____ _____ 1 Tongs, nickel-plated $15.46
_____ _____ 1 Flask, Erlenmeyer,
125ml
$4.69 _____ _____ 2 Watch glasses, 50mm $4.05
_____ _____ 1 Flask, Erlenmeyer,
250ml
$4.69 _____ _____ 1 Stir bar $3.55
_____ _____ 1 Funnel, glass, 65mm lg $9.76 _____ _____ 1 Thermometer $17.51
Lost or broken items should be replaced promptly.
The above items were received in good condition, as verified by signature below. I understand that these items are
solely my responsibility and that I must return everything I receive, also in good condition.
Checked-in by____________________________________________Date checked-in__________________________
Student Signature
TA Signature _____________________________________________Date __________________________
Loading page 7...
vii
Instructor’s Equipment List
Large Equipment
Cathode ray tube with power supply 1 per group
Capacitor setup (if not included with cathode ray tube) 1 per group
Commercial apparatus for Millikan oil drop 1 per group
Spectroscope 1 per group
Hydrogen lamp 1 per group
Mercury-vapor lamp 1 per group
Power supply for lamp 1 per group
Spectrometers 1 per group
Centrifuges (addition test tubes) 1 per group
Oven with insulated gloves 4-5 per room
Geiger counter 1 per group
Ring stands with ring and clamp 1 per student
Balances 4-5 per room
Bunsen burners with lighter 1 per student
Magnetic stirrer/hot plate 1 per 2-4 students
pH meter and buffers 1 per 3-5 students
Gel electrophoresis apparatus 1 per group
Hot plate/stirrers 1 per group
UV transilluminator and camera
Section Equipment
50 mL buret 1 per student
Buret clamp 1 per student
Filter flask 1 or more per group
Buchner funnels 1 or more per group
Porcelain crucible and cover 1 per student
Shooting mechanism 1 per group
Compass or string 1 per group
10-15 mL plastic centrifuge tube with cap 1 per group
Bar magnet 4-5 per room
Crystallization dish 1 per student
Ruler (in cm) 1 per student
1000-mL or larger beaker 1 per group
3-L or larger graduated cylinder 1 per section
2-L or larger graduated cylinder 1 per section
100-mL graduated cylinder 1 per group
25-mL graduated cylinder 1 per student or group
20-L or larger bucket 1-2 per section
40 feet tygon tubing – ¼ inch diameter 1-2 per section
Stopper (size 000) 1-2 per section
Meter stick or tape measurer 1 per group
#9 rubber stopper 1 per group
Instructor’s Equipment List
Large Equipment
Cathode ray tube with power supply 1 per group
Capacitor setup (if not included with cathode ray tube) 1 per group
Commercial apparatus for Millikan oil drop 1 per group
Spectroscope 1 per group
Hydrogen lamp 1 per group
Mercury-vapor lamp 1 per group
Power supply for lamp 1 per group
Spectrometers 1 per group
Centrifuges (addition test tubes) 1 per group
Oven with insulated gloves 4-5 per room
Geiger counter 1 per group
Ring stands with ring and clamp 1 per student
Balances 4-5 per room
Bunsen burners with lighter 1 per student
Magnetic stirrer/hot plate 1 per 2-4 students
pH meter and buffers 1 per 3-5 students
Gel electrophoresis apparatus 1 per group
Hot plate/stirrers 1 per group
UV transilluminator and camera
Section Equipment
50 mL buret 1 per student
Buret clamp 1 per student
Filter flask 1 or more per group
Buchner funnels 1 or more per group
Porcelain crucible and cover 1 per student
Shooting mechanism 1 per group
Compass or string 1 per group
10-15 mL plastic centrifuge tube with cap 1 per group
Bar magnet 4-5 per room
Crystallization dish 1 per student
Ruler (in cm) 1 per student
1000-mL or larger beaker 1 per group
3-L or larger graduated cylinder 1 per section
2-L or larger graduated cylinder 1 per section
100-mL graduated cylinder 1 per group
25-mL graduated cylinder 1 per student or group
20-L or larger bucket 1-2 per section
40 feet tygon tubing – ¼ inch diameter 1-2 per section
Stopper (size 000) 1-2 per section
Meter stick or tape measurer 1 per group
#9 rubber stopper 1 per group
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viii
Styrofoam cup 2 per student
Lid for cup (with hole for thermometer)* 1 per student
500-mL Erlenmeyer flask 2 per student or group
125-mL Erlenmeyer flask 6 per group
Backdrop material (aluminum foil, etc.)
Spray bottles 5-6 per section
Molecular model kit 1 per student
Paint brushes 1 per group
Plastic baby doll 1 per group
Heat gun 1-2 per group
Cotton broad cloth 1-2 yards per group
Knife 1 or more
5-6 all-purpose lighters (Aim-N-Flame)
Crystallization dish
800 mL or 1 L beaker 1 per student
Pencil
Black light (optional)
Scissors
1-mL pipet 1 per student
2-mL pipet 1 per student
5-mL pipet 1 per student
Cuvette (if required for spectrometer) 1 per student
White cloth cut into squares 1 yard per class
Alpha, beta, and gamma sources 1 per group
Piece of paper 1 per group
Piece of wood, ~1/4 inch thick 1 per group
Sheet of lead, ~1mm thick 1 per group
Thicker piece of lead 1 per group
Cobalt (blue) glass plates >2 per room
Stopwatch or timer 4-5 per room
Plexiglass box 13″ × 13″ × 13″ 1 per group
Styrofoam balls 2 3/8″ >23 per group
Target marbles >60 per group
Jumbo marbles >60 per group
Play balls 2.4′ or 60 mm >90 per group
Consumable materials
Filter paper
Food coloring
Marking pen
Weight boats (capable of holding 8 mL water)
Boiling chips
Laboratory soap
9″ Pasteur pipet
Pasteur pipet bulb
Balloons (7″ round)
Styrofoam cup 2 per student
Lid for cup (with hole for thermometer)* 1 per student
500-mL Erlenmeyer flask 2 per student or group
125-mL Erlenmeyer flask 6 per group
Backdrop material (aluminum foil, etc.)
Spray bottles 5-6 per section
Molecular model kit 1 per student
Paint brushes 1 per group
Plastic baby doll 1 per group
Heat gun 1-2 per group
Cotton broad cloth 1-2 yards per group
Knife 1 or more
5-6 all-purpose lighters (Aim-N-Flame)
Crystallization dish
800 mL or 1 L beaker 1 per student
Pencil
Black light (optional)
Scissors
1-mL pipet 1 per student
2-mL pipet 1 per student
5-mL pipet 1 per student
Cuvette (if required for spectrometer) 1 per student
White cloth cut into squares 1 yard per class
Alpha, beta, and gamma sources 1 per group
Piece of paper 1 per group
Piece of wood, ~1/4 inch thick 1 per group
Sheet of lead, ~1mm thick 1 per group
Thicker piece of lead 1 per group
Cobalt (blue) glass plates >2 per room
Stopwatch or timer 4-5 per room
Plexiglass box 13″ × 13″ × 13″ 1 per group
Styrofoam balls 2 3/8″ >23 per group
Target marbles >60 per group
Jumbo marbles >60 per group
Play balls 2.4′ or 60 mm >90 per group
Consumable materials
Filter paper
Food coloring
Marking pen
Weight boats (capable of holding 8 mL water)
Boiling chips
Laboratory soap
9″ Pasteur pipet
Pasteur pipet bulb
Balloons (7″ round)
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ix
Rubber bands
Tooth picks (plastic, round)
Plastic wrap (parafilm or aluminum foil)
Tape or staples/stapler
Nichrome wire
Candy pieces
Chalk
Ink
Meat drippings
Diet Coke (2 L bottles)
Mentos
pUC19 plasmid DNA solution
1 mL or similar-size microcentrifuge tubes
Alka Seltzer tablets
Ice
Tap water
Instructor’s Chemical List (note for section of 24 students)
3,3’,5,5’-tetramethylbenzidine solution <100 mL
4-(2-pyridylazo)resorcinol, monosodium salt hydrate <0.1 g
9,10-Bis(phenylethynyl)anthracene 0.12 g
9,10-Diphenylanthracene 0.12 g
Acetic acid 30 mL
Acetone 1.0 L
Agerose (gel quality) 10 g
Aluminum foil 3 rolls
Aluminum hydroxide 5 g
Ammonia-based cleaning solution or 6M NH4OH ~1 L
Ammonium acetate 80 mL
Ammonium carbonate monohydrate 6.0 g
Ammonium hydroxide <3 L
Ammonium oxalate <50 mL
Ammonium sulfate <50 mL
Ascorbic acid 10 g
Barium chloride 30 mL
Barium nitrate 5 g
Benzene 300 mL
Benzyl alcohol <100 mL
Bromophenol blue <20 mL
Butyric acid <200 mL
Cadmium ~1 kg
Calcium chloride 30 mL
Calcium sulfate 30 mL
Rubber bands
Tooth picks (plastic, round)
Plastic wrap (parafilm or aluminum foil)
Tape or staples/stapler
Nichrome wire
Candy pieces
Chalk
Ink
Meat drippings
Diet Coke (2 L bottles)
Mentos
pUC19 plasmid DNA solution
1 mL or similar-size microcentrifuge tubes
Alka Seltzer tablets
Ice
Tap water
Instructor’s Chemical List (note for section of 24 students)
3,3’,5,5’-tetramethylbenzidine solution <100 mL
4-(2-pyridylazo)resorcinol, monosodium salt hydrate <0.1 g
9,10-Bis(phenylethynyl)anthracene 0.12 g
9,10-Diphenylanthracene 0.12 g
Acetic acid 30 mL
Acetone 1.0 L
Agerose (gel quality) 10 g
Aluminum foil 3 rolls
Aluminum hydroxide 5 g
Ammonia-based cleaning solution or 6M NH4OH ~1 L
Ammonium acetate 80 mL
Ammonium carbonate monohydrate 6.0 g
Ammonium hydroxide <3 L
Ammonium oxalate <50 mL
Ammonium sulfate <50 mL
Ascorbic acid 10 g
Barium chloride 30 mL
Barium nitrate 5 g
Benzene 300 mL
Benzyl alcohol <100 mL
Bromophenol blue <20 mL
Butyric acid <200 mL
Cadmium ~1 kg
Calcium chloride 30 mL
Calcium sulfate 30 mL
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x
Chloroform 500 mL
Chromium ~1 kg
Chromium chloride hexahydrate <30 g
Cobalt chloride hexahydrate <50 g
Concentrated Hydrochloric acid 1-2 L
Concentrated Nitric acid 1-2 L
Concentrated (NH4)2Sx 80 mL
Concentrated Sulfuric acid 1-2 L
Copper (II) chloride 50.0 g
Copper sulfate pentahydrate <30 g
Copper wire 12 g
Corn starch ~50 g
Dichloromethane <3 L
Diethylenetriamine <1 L
Ethanol 2 L
Ethidium bromide <0.1g
Ethylenediamine <1 L
EDTA 1 g
FD&C #2, indigo carmine 5 mg
FD&C Red #40 <0.1 g
Ferric oxide powder ~500 g
Fluorescein 1.2 g
Formic acid <100 mL
Glacial acetic acid 50 mL
Glycerin < 10 mL
Hexanol <100 mL
Hydrogen peroxide <200 mL
Iron ~1 kg
Iron (III) nitrate (prepare fresh) 30 mL
Iron filings <10 g
Iron fillings 2.500 g
Iron sulfate (prepare fresh) 5 g
Isoamyl alcohol <100 mL
Isobutyl alcohol <100 mL
KHP (potassium hydrogen phthalate) 50 g
Lemon juice ~500 mL
Leucomalachite green solution <100 mL
Lithium chloride 10.0 g
Lithium metal 5 g
Lithium nitrate 5 g
Luminol (3-aminophthalhydrazine) 2.4 g
Chloroform 500 mL
Chromium ~1 kg
Chromium chloride hexahydrate <30 g
Cobalt chloride hexahydrate <50 g
Concentrated Hydrochloric acid 1-2 L
Concentrated Nitric acid 1-2 L
Concentrated (NH4)2Sx 80 mL
Concentrated Sulfuric acid 1-2 L
Copper (II) chloride 50.0 g
Copper sulfate pentahydrate <30 g
Copper wire 12 g
Corn starch ~50 g
Dichloromethane <3 L
Diethylenetriamine <1 L
Ethanol 2 L
Ethidium bromide <0.1g
Ethylenediamine <1 L
EDTA 1 g
FD&C #2, indigo carmine 5 mg
FD&C Red #40 <0.1 g
Ferric oxide powder ~500 g
Fluorescein 1.2 g
Formic acid <100 mL
Glacial acetic acid 50 mL
Glycerin < 10 mL
Hexanol <100 mL
Hydrogen peroxide <200 mL
Iron ~1 kg
Iron (III) nitrate (prepare fresh) 30 mL
Iron filings <10 g
Iron fillings 2.500 g
Iron sulfate (prepare fresh) 5 g
Isoamyl alcohol <100 mL
Isobutyl alcohol <100 mL
KHP (potassium hydrogen phthalate) 50 g
Lemon juice ~500 mL
Leucomalachite green solution <100 mL
Lithium chloride 10.0 g
Lithium metal 5 g
Lithium nitrate 5 g
Luminol (3-aminophthalhydrazine) 2.4 g
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xi
Magnesium chloride 5 g
Magnesium hydroxide 5 g
Magnesium sulfate 25 g
Malonic acid 100 g
Manganese ~1 kg
Mercurous chloride <5 mL
Methanol 7 L
Methyl red <0.1 g
Methyl salicylate <5 mL
Methyl violet in dropper bottle 20 mL
Methylene chloride 30 mL
Naphthalene <300 g
Nickle sulfate septahydrate 70 g
Octanol <100 mL
Oleic acid 0.02 g
Oxalyl chloride in dichloromethane <100 mL
Para nitrophenyl phosphate, disodium salt hexahydrate 25 mL
para-dichlorobenzene 25 g
Picolinic acid 1 g
Phenolphthalein 1 L
Potassium bromate 100 g
Potassium chloride 5 g
Potassium dichromate <10 mL
Potassium ferrocyanide <10 mL
Potassium metal 5 g
Potassium nitrate 300 g
Potassium permanganate 30 mL
Potassium thiocyanate <15 mL
Propanol <100 mL
Propionic acid <100 mL
Prostatic acid phosphatase (bovine) 25 mL
Red #40 0.125 g
Rhodamine B 1.2 g
Salicylic acid 50 g
Saturated barium hydroxide <50 mL
Saturated M silver nitrate <125 mL
Silver sulfate <10 g
Sodium acetate <2 g
Sodium bicarbonate 300 g
Sodium bismuthate 15 g
Sodium carbonate 48.0 g
Magnesium chloride 5 g
Magnesium hydroxide 5 g
Magnesium sulfate 25 g
Malonic acid 100 g
Manganese ~1 kg
Mercurous chloride <5 mL
Methanol 7 L
Methyl red <0.1 g
Methyl salicylate <5 mL
Methyl violet in dropper bottle 20 mL
Methylene chloride 30 mL
Naphthalene <300 g
Nickle sulfate septahydrate 70 g
Octanol <100 mL
Oleic acid 0.02 g
Oxalyl chloride in dichloromethane <100 mL
Para nitrophenyl phosphate, disodium salt hexahydrate 25 mL
para-dichlorobenzene 25 g
Picolinic acid 1 g
Phenolphthalein 1 L
Potassium bromate 100 g
Potassium chloride 5 g
Potassium dichromate <10 mL
Potassium ferrocyanide <10 mL
Potassium metal 5 g
Potassium nitrate 300 g
Potassium permanganate 30 mL
Potassium thiocyanate <15 mL
Propanol <100 mL
Propionic acid <100 mL
Prostatic acid phosphatase (bovine) 25 mL
Red #40 0.125 g
Rhodamine B 1.2 g
Salicylic acid 50 g
Saturated barium hydroxide <50 mL
Saturated M silver nitrate <125 mL
Silver sulfate <10 g
Sodium acetate <2 g
Sodium bicarbonate 300 g
Sodium bismuthate 15 g
Sodium carbonate 48.0 g
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xii
Sodium citrate 5 g
Sodium chloride 50.0 g
Sodium hydrogen carbonate 5 g
Sodium hydrogen phosphate <5 mL
Sodium hydroxide 5-6 L
Sodium hypochlorite 30 mL
Sodium metal 5 g
Sodium nitrate 5 g
Stearic acid 5 g
Strontium chloride 10 g
Sucrose 10 g
Thioacetamide 410 g
Tin 10 g
Tin chloride ~1 kg
TRIS-acetate 1 g
Xylene cyanol FF 1 g
Zinc 2.5 g
Zinc oxide ~1 kg
Sodium citrate 5 g
Sodium chloride 50.0 g
Sodium hydrogen carbonate 5 g
Sodium hydrogen phosphate <5 mL
Sodium hydroxide 5-6 L
Sodium hypochlorite 30 mL
Sodium metal 5 g
Sodium nitrate 5 g
Stearic acid 5 g
Strontium chloride 10 g
Sucrose 10 g
Thioacetamide 410 g
Tin 10 g
Tin chloride ~1 kg
TRIS-acetate 1 g
Xylene cyanol FF 1 g
Zinc 2.5 g
Zinc oxide ~1 kg
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1
Experiment 1
Laboratory Basics: Accuracy and Precision – Who’s the Shooting
Champion?
For the Instructor
This lab is designed to add fun and excitement to the traditional first experiment in the first-semester
general chemistry laboratory. For shooting at a target, we would recommend being open to
experimentation. A large catapult throwing water balloons at a large target such as a sheet painted
with a bull’s eye, a paint ball gun and target, blunt-tipped arrows shot into a target mounted on a thin
piece of styrofoam, throwing horseshoes, rolling balls into a bull’s eye, throwing small bean bags
(as in tail gate toss) at a target, chipping golf balls at a flag, or even just darts and a dart board can be
considered. A safe indoor alternative is foam dart guns; these darts can be fired at a target drawn on a
dry erase board or chalk board. Cost is only around $10, and they can be found at most toy stores.
Moistening the end of the suction cups helps the dart to adhere to the target.
In our experience, 10 mL disposable plastic centrifuge tubes are surprisingly accurate, just as accurate
within error as 10 mL graduated cylinders. However, because the tubes have fewer graduations,
estimating the last significant figure when adding a given mass of water is more difficult. We have
also found that the reproducibility of measuring 8 mL of water is greater with the plastic tubes
compared to the graduated cylinder as it is easier in the plastic to gently tape the container to remove
air bubbles and water droplets clinging to the side.
Preparation Information – 24 students
Shooting mechanism (refer to previous discussion) 1 per group
Compass or string
10- or 15-mL plastic centrifuge tube with cap 1 per group
Weight boats (capable of holding 8 mL water) 1 per group
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Balance 4 or 5 per room
10-mL graduated cylinder 1 per group
Experiment 1
Laboratory Basics: Accuracy and Precision – Who’s the Shooting
Champion?
For the Instructor
This lab is designed to add fun and excitement to the traditional first experiment in the first-semester
general chemistry laboratory. For shooting at a target, we would recommend being open to
experimentation. A large catapult throwing water balloons at a large target such as a sheet painted
with a bull’s eye, a paint ball gun and target, blunt-tipped arrows shot into a target mounted on a thin
piece of styrofoam, throwing horseshoes, rolling balls into a bull’s eye, throwing small bean bags
(as in tail gate toss) at a target, chipping golf balls at a flag, or even just darts and a dart board can be
considered. A safe indoor alternative is foam dart guns; these darts can be fired at a target drawn on a
dry erase board or chalk board. Cost is only around $10, and they can be found at most toy stores.
Moistening the end of the suction cups helps the dart to adhere to the target.
In our experience, 10 mL disposable plastic centrifuge tubes are surprisingly accurate, just as accurate
within error as 10 mL graduated cylinders. However, because the tubes have fewer graduations,
estimating the last significant figure when adding a given mass of water is more difficult. We have
also found that the reproducibility of measuring 8 mL of water is greater with the plastic tubes
compared to the graduated cylinder as it is easier in the plastic to gently tape the container to remove
air bubbles and water droplets clinging to the side.
Preparation Information – 24 students
Shooting mechanism (refer to previous discussion) 1 per group
Compass or string
10- or 15-mL plastic centrifuge tube with cap 1 per group
Weight boats (capable of holding 8 mL water) 1 per group
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Balance 4 or 5 per room
10-mL graduated cylinder 1 per group
Loading page 14...
Experiment 1: Laboratory Basics: Accuracy and Precision – Who’s the Shooting Champion?
2
Answers to Pre-Laboratory Questions
1. William Tell had only one shot to shoot an apple from the top of his son’s head with his bow and
arrow. If you were William Tell and you loved your son, would you rather be accurate or precise?
Explain why.
Accurate – hit the apple. Precise refers to reproducibility, which is not applicable with one shot.
2. Assume that you found that the average volume of water required to fill the graduated cylinder to
the 8.00 mL mark was 7.95 mL. Calculate the % error.
(7.95 mL − 8.00 mL)/8.00 mL × 100% = 6%
2
Answers to Pre-Laboratory Questions
1. William Tell had only one shot to shoot an apple from the top of his son’s head with his bow and
arrow. If you were William Tell and you loved your son, would you rather be accurate or precise?
Explain why.
Accurate – hit the apple. Precise refers to reproducibility, which is not applicable with one shot.
2. Assume that you found that the average volume of water required to fill the graduated cylinder to
the 8.00 mL mark was 7.95 mL. Calculate the % error.
(7.95 mL − 8.00 mL)/8.00 mL × 100% = 6%
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3
Experiment 2
Components of a Mixture – What Is That Stuff in the Bottom of the
Cereal Box?
For the Instructor
The mixture per student should contain approximately 5 mg red #40, 100 mg Fe, 100 mg ZnO,
200 mg stearic acid, and 395 mg sucrose per gram. If the sucrose crystals are large, they might take a
considerable time to dissolve, and grinding the sucrose before making the mixture is advisable.
The concentration of the methanol solution from 200 to 5-10 mL will take longer than a single lab
period. This process can be facilitated by placing in a well-ventilated hood. During the following
week, someone will need to check these and move them to a freezer at the appropriate time. Very
little time will be required during the next laboratory period to complete the experiment.
This experiment can be performed much faster if gravity filtration is replaced with the use of a
Buchner funnel, filter flask, and vacuum source.
Preparation Information – 24 students
Methanol ~6 L
Chloroform <500 mL
(mixture – 25 g) ~25 g per section
Iron fillings 2.500 grams
Zinc oxide 2.500 grams
Sucrose 9.875 grams
Red #40 0.125 grams
Stearic acid 5.000 grams
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Filter paper
Weigh boats/weighing paper
Funnel 1 per student
Beaker (20 mL) 2 per student
Beaker (400 mL) 2 per student
10-mL graduated cylinder 1 per student (optional)
100-mL graduated cylinder 1 per student (optional)
Ring stand 1 per student
Iron ring 1 per student
Experiment 2
Components of a Mixture – What Is That Stuff in the Bottom of the
Cereal Box?
For the Instructor
The mixture per student should contain approximately 5 mg red #40, 100 mg Fe, 100 mg ZnO,
200 mg stearic acid, and 395 mg sucrose per gram. If the sucrose crystals are large, they might take a
considerable time to dissolve, and grinding the sucrose before making the mixture is advisable.
The concentration of the methanol solution from 200 to 5-10 mL will take longer than a single lab
period. This process can be facilitated by placing in a well-ventilated hood. During the following
week, someone will need to check these and move them to a freezer at the appropriate time. Very
little time will be required during the next laboratory period to complete the experiment.
This experiment can be performed much faster if gravity filtration is replaced with the use of a
Buchner funnel, filter flask, and vacuum source.
Preparation Information – 24 students
Methanol ~6 L
Chloroform <500 mL
(mixture – 25 g) ~25 g per section
Iron fillings 2.500 grams
Zinc oxide 2.500 grams
Sucrose 9.875 grams
Red #40 0.125 grams
Stearic acid 5.000 grams
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Filter paper
Weigh boats/weighing paper
Funnel 1 per student
Beaker (20 mL) 2 per student
Beaker (400 mL) 2 per student
10-mL graduated cylinder 1 per student (optional)
100-mL graduated cylinder 1 per student (optional)
Ring stand 1 per student
Iron ring 1 per student
Loading page 16...
Experiment 2: Components of a Mixture – What Is That Stuff in the Bottom of the Cereal Box?
4
Clay triangle 1 per student
Stirring rod 1 per student
Wash bottle 2 per 1-4 students
Spatula 1 per student
Bar magnet 1 per 1-4 students
Rubber policeman 1 per student
Magnetic stirrer/hot plate 1 per 2-4 students (optional)
Balance 4-5 per room
Answers to Pre-Laboratory Questions
1. How could you determine (without tasting) whether a container of a colorless liquid contained
ethanol or ethanol and sucrose?
Allow the ethanol to evaporate; a white crystalline solid left would indicate the presence of
sucrose.
2. Does this experiment demonstrate the law of conservation of matter?
No. No chemical reactions are involved, only physical separations.
3. Explain the difference between filtration and decantation (see the “Experiment Equipment and
Procedures” section of this manual). Why might one want to use filtration in this experiment
rather than decantation?
Decanting works if solid(s) stay at the bottom of the container. If they are likely to be disturbed,
then filtration should be used.
4. How could one rapidly separate red #40 from zinc oxide? Indicate every step.
Add water and agitate to dissolve the red #40. Filter and wash the solid with water. Solid
remaining is zinc oxide.
5. Separation techniques are performed on a sample containing sand and salt. It was determined that
there were 5.43 g of sand and 4.52 g of salt. The total sample weight was 10.50 g. What is the
percent recovery of sand from the sample?
(5.43 g + 4.52 g)/10.50 g 100% = 94.8%
4
Clay triangle 1 per student
Stirring rod 1 per student
Wash bottle 2 per 1-4 students
Spatula 1 per student
Bar magnet 1 per 1-4 students
Rubber policeman 1 per student
Magnetic stirrer/hot plate 1 per 2-4 students (optional)
Balance 4-5 per room
Answers to Pre-Laboratory Questions
1. How could you determine (without tasting) whether a container of a colorless liquid contained
ethanol or ethanol and sucrose?
Allow the ethanol to evaporate; a white crystalline solid left would indicate the presence of
sucrose.
2. Does this experiment demonstrate the law of conservation of matter?
No. No chemical reactions are involved, only physical separations.
3. Explain the difference between filtration and decantation (see the “Experiment Equipment and
Procedures” section of this manual). Why might one want to use filtration in this experiment
rather than decantation?
Decanting works if solid(s) stay at the bottom of the container. If they are likely to be disturbed,
then filtration should be used.
4. How could one rapidly separate red #40 from zinc oxide? Indicate every step.
Add water and agitate to dissolve the red #40. Filter and wash the solid with water. Solid
remaining is zinc oxide.
5. Separation techniques are performed on a sample containing sand and salt. It was determined that
there were 5.43 g of sand and 4.52 g of salt. The total sample weight was 10.50 g. What is the
percent recovery of sand from the sample?
(5.43 g + 4.52 g)/10.50 g 100% = 94.8%
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5
Experiment 3
Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number
For the Instructor
We believe it is very important that students actually measure a fundamental constant or another
important number used in general chemistry lectures. Given the emphasis placed on the charge on an
electron in most general chemistry textbooks, this is our fundamental constant of choice.
Unfortunately, this determination cannot be performed with normal general chemistry laboratory
equipment; in fact, the equipment is rather expensive compared to most general chemistry equipment.
If we had ideal conditions and budgets, we would have students measure the charge to mass ratio on
an electron using a commercial system sold by Pasco (www.pasco.com) and then use a commercial
system to perform the Millikan oil drop experiment (also sold by Pasco and other companies);
however, the apparatuses cost $1,500 to $2,500.
Students can more affordably look at the behavior of electrons in cathode ray tubes ($500-$1,000 for
a commercial setup and power supply, available from many science education equipment suppliers).
We particularly like the cathode ray tubes with electrodes for applying a magnetic field built in (at the
time of writing, ~$250 from Sci-Supply plus the cost of a power supply). An alternative is to use an
oscilloscope, as it contains a cathode ray tube. Instructors may already possess one in their department
or be able to borrow one from their institution’s electrician or physics department. In addition to
deflecting the path of the electrons of a cathode ray tube with magnets, the path can be altered by
applying an electric field with a capacitor (if one is not built into the unit); these are also available
(<$500 plus power supply) from many science education equipment suppliers. This again is not an
insignificant cost, while one might be able to borrow these from a neighboring physics department.
Fortunately, obtaining a reasonable value for Avogadro’s number can be accomplished cheaply and
easily in a time-tested experiment. This can also be performed as a demonstration by placing the
watch glass on an overhead projector.
To form a monolayer requires only a few drops of the oleic acid solution. If students use more than 20
drops, they are probably forming multiple layers. Also, in our experience, students should be walked
through the calculations in a lecture.
Experiment 3
Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number
For the Instructor
We believe it is very important that students actually measure a fundamental constant or another
important number used in general chemistry lectures. Given the emphasis placed on the charge on an
electron in most general chemistry textbooks, this is our fundamental constant of choice.
Unfortunately, this determination cannot be performed with normal general chemistry laboratory
equipment; in fact, the equipment is rather expensive compared to most general chemistry equipment.
If we had ideal conditions and budgets, we would have students measure the charge to mass ratio on
an electron using a commercial system sold by Pasco (www.pasco.com) and then use a commercial
system to perform the Millikan oil drop experiment (also sold by Pasco and other companies);
however, the apparatuses cost $1,500 to $2,500.
Students can more affordably look at the behavior of electrons in cathode ray tubes ($500-$1,000 for
a commercial setup and power supply, available from many science education equipment suppliers).
We particularly like the cathode ray tubes with electrodes for applying a magnetic field built in (at the
time of writing, ~$250 from Sci-Supply plus the cost of a power supply). An alternative is to use an
oscilloscope, as it contains a cathode ray tube. Instructors may already possess one in their department
or be able to borrow one from their institution’s electrician or physics department. In addition to
deflecting the path of the electrons of a cathode ray tube with magnets, the path can be altered by
applying an electric field with a capacitor (if one is not built into the unit); these are also available
(<$500 plus power supply) from many science education equipment suppliers. This again is not an
insignificant cost, while one might be able to borrow these from a neighboring physics department.
Fortunately, obtaining a reasonable value for Avogadro’s number can be accomplished cheaply and
easily in a time-tested experiment. This can also be performed as a demonstration by placing the
watch glass on an overhead projector.
To form a monolayer requires only a few drops of the oleic acid solution. If students use more than 20
drops, they are probably forming multiple layers. Also, in our experience, students should be walked
through the calculations in a lecture.
Loading page 18...
Experiment 3: Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number
6
Cathode ray tube
Preparation Information – 24 students
Cathode ray tube with power supply 1 per group
Bar magnets >1 per group
Capacitor setup (if not included with cathode ray tube) 1 per group
Millikan oil drop
Preparation Information – 24 students
Commercial apparatus 1 per group
Avogadro’s Number (24 students)
Benzene is a possible carcinogen. Benzene-containing solution must not be disposed of down the
drain. The oleic acid/benzene solution should have a concentration of 0.02 g oleic acid per L solution.
The methyl violet solution should be about 0.5%. A class of 24 should need ~0.5 L of oleic
acid/benzene solution, <250 mL benezene, and <20 mL of 0.5% methyl violet solution per class of 24.
Placing the ammonia-based cleaning solution in a wash bottle for students to use is recommended; the
glassware is easier to clean in this manner, while the students use less of the solution.
A pipetter that dispenses a volume of 10 L could be used to replace the Pasteur pipet and calibration
process.
Preparation Information – 24 students
Oleic acid 0.02 g for solution
Benzene 300 mL
Methyl violet solution in dropping bottle 20 mL
Ammonia-based cleaning solution or 6 M NH4OH ~1 L
Deionized or distilled water
Laboratory soap
Necessary Equipment – 24 students
9″ Pasteur pipet 2 per student
Pasteur pipet bulb 1 per student
4-inch watch glass 1 pert student
Dropping bottle 1 per class
10 mL beaker 1 per student
5- or 10-mL graduated cylinder
or 1-mL volumetric tube 1 per student
Ruler (in cm) 1 per 4-6 students
Paper towels
Disposable gloves
6
Cathode ray tube
Preparation Information – 24 students
Cathode ray tube with power supply 1 per group
Bar magnets >1 per group
Capacitor setup (if not included with cathode ray tube) 1 per group
Millikan oil drop
Preparation Information – 24 students
Commercial apparatus 1 per group
Avogadro’s Number (24 students)
Benzene is a possible carcinogen. Benzene-containing solution must not be disposed of down the
drain. The oleic acid/benzene solution should have a concentration of 0.02 g oleic acid per L solution.
The methyl violet solution should be about 0.5%. A class of 24 should need ~0.5 L of oleic
acid/benzene solution, <250 mL benezene, and <20 mL of 0.5% methyl violet solution per class of 24.
Placing the ammonia-based cleaning solution in a wash bottle for students to use is recommended; the
glassware is easier to clean in this manner, while the students use less of the solution.
A pipetter that dispenses a volume of 10 L could be used to replace the Pasteur pipet and calibration
process.
Preparation Information – 24 students
Oleic acid 0.02 g for solution
Benzene 300 mL
Methyl violet solution in dropping bottle 20 mL
Ammonia-based cleaning solution or 6 M NH4OH ~1 L
Deionized or distilled water
Laboratory soap
Necessary Equipment – 24 students
9″ Pasteur pipet 2 per student
Pasteur pipet bulb 1 per student
4-inch watch glass 1 pert student
Dropping bottle 1 per class
10 mL beaker 1 per student
5- or 10-mL graduated cylinder
or 1-mL volumetric tube 1 per student
Ruler (in cm) 1 per 4-6 students
Paper towels
Disposable gloves
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Experiment 3: Cathode Ray Tubes, Millikan Oil Drop, and Avogadro’s Number
7
Answers to Pre-Laboratory Questions
1. Oleic acid is a fatty acid and is essentially immiscible (insoluble in water). Given this, why do you
think that the glass surfaces in this experiment must be cleaned so carefully?
Oleic acid may interact and stick to oil residue on glass surface rather than form layer on top of
water.
2. Find a material safety data sheet (MSDS) for benzene on the Internet. What are the hazards
associated with working with benzene? What precautions should be taken?
A Google search of “MSDS benzene” will provide many examples. Hazards include
carcinogenic, possibly mutagenic, and developmental toxins. Wear splash goggles, lab coat, and
gloves.
7
Answers to Pre-Laboratory Questions
1. Oleic acid is a fatty acid and is essentially immiscible (insoluble in water). Given this, why do you
think that the glass surfaces in this experiment must be cleaned so carefully?
Oleic acid may interact and stick to oil residue on glass surface rather than form layer on top of
water.
2. Find a material safety data sheet (MSDS) for benzene on the Internet. What are the hazards
associated with working with benzene? What precautions should be taken?
A Google search of “MSDS benzene” will provide many examples. Hazards include
carcinogenic, possibly mutagenic, and developmental toxins. Wear splash goggles, lab coat, and
gloves.
Loading page 20...
8
Experiment 4
Conservation of Mass and Reaction Types – Copper Recovery Cycle
For the Instructor
This is a very conventional experiment, found in many laboratory books. This is because it is
straightforward and directly illustrates concepts from the textbook. In other words, it works and
illustrates concepts well; thus, students like it, and therefore we like it.
Students should be warned about handing strong acids (HNO3 and H2SO4) and bases (NaOH).
Copper-containing solutions (as with all solutions containing transition metals) should not be disposed
of down the sink.
This lab can be longer than the normal 2½- to 3-hour laboratory session, although we have had the
students complete the experiment in 2½ hours. The experiment may be stopped after any of the steps.
The solutions or solids need only be covered and saved until the next session. If the necessary
equipment is available, time can be saved by having the students use two filtration setups.
Preparation Information – 24 students
Aluminum foil
Copper wire 12 g (0.5 g per student)
Conc. Nitric Acid 240 mL
Conc. Hydrochloric Acid 24 mL
3.0 M NaOH 1 L
6 M Sulfuric Acid 360 mL
Methanol 120 mL
Acetone 120 mL
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Red Litmus paper
Boiling chips 2-3 per student
Filter paper
Weigh boats or weighing paper
Bunsen burner 1 per student
Evaporating dish 1 per student
Wire triangle 1 per student
Funnel 1 per student
10-mL graduated cylinder 1 per student
100-mL graduated cylinder 1 per student
250-mL Erlenmeyer flask 2 per student
250-mL beaker 2 per student
Experiment 4
Conservation of Mass and Reaction Types – Copper Recovery Cycle
For the Instructor
This is a very conventional experiment, found in many laboratory books. This is because it is
straightforward and directly illustrates concepts from the textbook. In other words, it works and
illustrates concepts well; thus, students like it, and therefore we like it.
Students should be warned about handing strong acids (HNO3 and H2SO4) and bases (NaOH).
Copper-containing solutions (as with all solutions containing transition metals) should not be disposed
of down the sink.
This lab can be longer than the normal 2½- to 3-hour laboratory session, although we have had the
students complete the experiment in 2½ hours. The experiment may be stopped after any of the steps.
The solutions or solids need only be covered and saved until the next session. If the necessary
equipment is available, time can be saved by having the students use two filtration setups.
Preparation Information – 24 students
Aluminum foil
Copper wire 12 g (0.5 g per student)
Conc. Nitric Acid 240 mL
Conc. Hydrochloric Acid 24 mL
3.0 M NaOH 1 L
6 M Sulfuric Acid 360 mL
Methanol 120 mL
Acetone 120 mL
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Red Litmus paper
Boiling chips 2-3 per student
Filter paper
Weigh boats or weighing paper
Bunsen burner 1 per student
Evaporating dish 1 per student
Wire triangle 1 per student
Funnel 1 per student
10-mL graduated cylinder 1 per student
100-mL graduated cylinder 1 per student
250-mL Erlenmeyer flask 2 per student
250-mL beaker 2 per student
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Experiment 4: Conservation of Mass and Reaction Types – Copper Recovery Cycle
9
Beaker to use with evaporating dish to make steam bath
Stirring rod 1 per student
Ring stand and iron ring 1 per student
Wire gauze 1 set per student
Rubber policeman 1 per student
Hot plates (optional) 1 per student
Balance 4 or 5 per room
Answers to Pre-Laboratory Questions
1. List the hazards involved in this experiment. What can you do to minimize the chances of
anything bad happening in each case?
Sulfuric acid and nitric acid are strong acids, while sodium hydroxide is a strong base. Be
careful and wear gloves and goggles; lab coats are a good suggestion. Immediately wash any
skin or clothing that comes in contact. Wash surfaces that come in contact so that someone else
is not exposed accidentally. Have appropriate spill kits nearby.
2. Name the gas produced when nitric acid is added to copper metal.
Nitrogen dioxide
3. During your experiment, you use 0.597 g of copper to start your reaction. After you carry through
all the different steps, you recover 0.684 g of copper. What is the percent recovery of copper?
Since it appears that you may have created matter (which is not possible in this experiment), what
could be a source of error?
(0.597 g – 0.684 g)/0.597 g 100% = 146%. Solid not properly dried is most obvious
possibility.
4. Identify the reaction types in equations 1, 2, 4, and 5. Indicate why you made these choices
(e.g., indicate gaseous products, precipitates, etc.).
Eqn. 1 – gas forming – NO2 (g). Also redox – Cu0 → Cu2+; N+5 → N+4
Eqn. 2 – precipitation – Cu(OH)2 (s)
Eqn. 4 – acid base – O2− + 2H+ → H2O
Eqn. 5 – redox – Cu2+ → Cu0; Al0 → Al3+
9
Beaker to use with evaporating dish to make steam bath
Stirring rod 1 per student
Ring stand and iron ring 1 per student
Wire gauze 1 set per student
Rubber policeman 1 per student
Hot plates (optional) 1 per student
Balance 4 or 5 per room
Answers to Pre-Laboratory Questions
1. List the hazards involved in this experiment. What can you do to minimize the chances of
anything bad happening in each case?
Sulfuric acid and nitric acid are strong acids, while sodium hydroxide is a strong base. Be
careful and wear gloves and goggles; lab coats are a good suggestion. Immediately wash any
skin or clothing that comes in contact. Wash surfaces that come in contact so that someone else
is not exposed accidentally. Have appropriate spill kits nearby.
2. Name the gas produced when nitric acid is added to copper metal.
Nitrogen dioxide
3. During your experiment, you use 0.597 g of copper to start your reaction. After you carry through
all the different steps, you recover 0.684 g of copper. What is the percent recovery of copper?
Since it appears that you may have created matter (which is not possible in this experiment), what
could be a source of error?
(0.597 g – 0.684 g)/0.597 g 100% = 146%. Solid not properly dried is most obvious
possibility.
4. Identify the reaction types in equations 1, 2, 4, and 5. Indicate why you made these choices
(e.g., indicate gaseous products, precipitates, etc.).
Eqn. 1 – gas forming – NO2 (g). Also redox – Cu0 → Cu2+; N+5 → N+4
Eqn. 2 – precipitation – Cu(OH)2 (s)
Eqn. 4 – acid base – O2− + 2H+ → H2O
Eqn. 5 – redox – Cu2+ → Cu0; Al0 → Al3+
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10
Experiment 5
Equivalent Weights and the Periodic Table
For the Instructor
Students should be instructed about the concerns associated with the use of corrosive materials.
Students may desire to wear gloves. The aqueous solutions resulting from filtering and washing the
unreacted metals are not suitable to be poured down the drain. The solution for each metal should be
placed in a separate labeled waste container.
Helium quality balloons should be used. The quality of the balloons used is important. If helium
quality balloons are not used, the highest quality available should be used. If lower quality balloons
are used, then the time used to collect the hydrogen gas should be minimized to prevent gas loss.
This experiment is best performed over three weeks. At the end of lab 4 (or whatever lab is performed
before this one), students should go ahead and label everything, weigh out the metal samples, and place
them into the appropriate balloons. This way the next week the acid can be placed in the tubes and the
metal added early in the lab period to maximize the time for Fe, Mn, and Cr to react with the acid. The
third week the Cd, Zn, and Sn portion can be completed. If the reactions with Zn, Cd, and Zn go to
completion well before the third laboratory period, someone should measure the volume of the
balloons promptly. This is preferably done after one day. If necessary, the reactions can be terminated
at the same time as those of Fe, Mn, and Cr; the volume and mass changes will just be small.
The results of this experiment are designed to be used in conjunction with those of experiment 8.
Preparation Information – 24 students
Manganese 24 g
Chromium 24 g
Iron 24 g
Zinc 24 g
Cadmium 36 g
Tin 36 g
Concentrated hydrochloric acid 300 mL
Ethanol 500 mL
Necessary Equipment – 24 students
Weigh boats
Paper towels
Marking pen
Filter paper
1000-mL or larger beaker 1 per group
Test tubes (15 mm × 150 mm) 6 per group
Experiment 5
Equivalent Weights and the Periodic Table
For the Instructor
Students should be instructed about the concerns associated with the use of corrosive materials.
Students may desire to wear gloves. The aqueous solutions resulting from filtering and washing the
unreacted metals are not suitable to be poured down the drain. The solution for each metal should be
placed in a separate labeled waste container.
Helium quality balloons should be used. The quality of the balloons used is important. If helium
quality balloons are not used, the highest quality available should be used. If lower quality balloons
are used, then the time used to collect the hydrogen gas should be minimized to prevent gas loss.
This experiment is best performed over three weeks. At the end of lab 4 (or whatever lab is performed
before this one), students should go ahead and label everything, weigh out the metal samples, and place
them into the appropriate balloons. This way the next week the acid can be placed in the tubes and the
metal added early in the lab period to maximize the time for Fe, Mn, and Cr to react with the acid. The
third week the Cd, Zn, and Sn portion can be completed. If the reactions with Zn, Cd, and Zn go to
completion well before the third laboratory period, someone should measure the volume of the
balloons promptly. This is preferably done after one day. If necessary, the reactions can be terminated
at the same time as those of Fe, Mn, and Cr; the volume and mass changes will just be small.
The results of this experiment are designed to be used in conjunction with those of experiment 8.
Preparation Information – 24 students
Manganese 24 g
Chromium 24 g
Iron 24 g
Zinc 24 g
Cadmium 36 g
Tin 36 g
Concentrated hydrochloric acid 300 mL
Ethanol 500 mL
Necessary Equipment – 24 students
Weigh boats
Paper towels
Marking pen
Filter paper
1000-mL or larger beaker 1 per group
Test tubes (15 mm × 150 mm) 6 per group
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Experiment 5: Equivalent Weights and the Periodic Table
11
Balloons (7″ round) 7 per group
Test-tube rack 1 per group
Rubber bands up to 6 per group
Filter flask 1 or more per group
Buchner Funnels 1 or more per group
Wash bottle 2 per group
Spatula 1 or more per group
Test-tube holder 1 or more per group
Hot plate 1 per group
3 L or larger graduated cylinder 1 per lab section
Balances 4-5 per room
Answers to Pre-Laboratory Questions
1. What is the valence for the six metals based on their reaction with hydrochloric acid?
Cr − 3
Mn − 2
Fe − 2
Zn − 2
Cd − 2
Sn − 2
2. How are atomic weights determined experimentally at the current time?
Mass spectrometry is the most obvious answer from freshman textbooks.
3. What safety precautions are necessary in this experiment?
Hydrochloric acid is a strong acid. Be careful and wear gloves and goggles; lab coats are a good
suggestion. Immediately wash any skin or clothing that comes in contact. Wash surfaces that
come in contact so that someone else is not exposed accidentally. Have appropriate spill kit
nearby.
11
Balloons (7″ round) 7 per group
Test-tube rack 1 per group
Rubber bands up to 6 per group
Filter flask 1 or more per group
Buchner Funnels 1 or more per group
Wash bottle 2 per group
Spatula 1 or more per group
Test-tube holder 1 or more per group
Hot plate 1 per group
3 L or larger graduated cylinder 1 per lab section
Balances 4-5 per room
Answers to Pre-Laboratory Questions
1. What is the valence for the six metals based on their reaction with hydrochloric acid?
Cr − 3
Mn − 2
Fe − 2
Zn − 2
Cd − 2
Sn − 2
2. How are atomic weights determined experimentally at the current time?
Mass spectrometry is the most obvious answer from freshman textbooks.
3. What safety precautions are necessary in this experiment?
Hydrochloric acid is a strong acid. Be careful and wear gloves and goggles; lab coats are a good
suggestion. Immediately wash any skin or clothing that comes in contact. Wash surfaces that
come in contact so that someone else is not exposed accidentally. Have appropriate spill kit
nearby.
Loading page 24...
12
Experiment 6
Hydrates
For the Instructor
Concentrated nitric acid (~15 M) should be carefully diluted in 2.5 fold to give ~6 M HNO3.
Preparation Information − 24 students
CoCl2·6H2O <30 g
CuSO4·5H2O <30 g
CrCl3·6H2O <30 g
6 M nitric acid <2 L
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Large beaker for acid bath 1 or more per class
Porcelain crucible and cover 1 per student
Crucible tongs 1 per student
Ring stand with ring 1 per student
Clay triangle 1 per student
Pasteur pipet and bulb or dropper 1 per student
Blue litmus paper 1 piece per student
Bunsen burner 1 per student
Lighter for burner 1 per 1-4 students
Analytical balance (4 decimal places) 4-5 per room
Answers to Pre-Laboratory Questions
1. If a hydrate of the formula MCly·xH2O decomposes when heated to produce HCl, what change
would you expect to occur when a piece of blue litmus paper is held in the path of the vapor
released? Explain.
The blue litmus paper should turn red as blue litmus paper turns red in the presence of acid and
HCl is hydrochloric acid.
Experiment 6
Hydrates
For the Instructor
Concentrated nitric acid (~15 M) should be carefully diluted in 2.5 fold to give ~6 M HNO3.
Preparation Information − 24 students
CoCl2·6H2O <30 g
CuSO4·5H2O <30 g
CrCl3·6H2O <30 g
6 M nitric acid <2 L
Necessary Equipment – 24 students
Paper towels
Disposable gloves
Large beaker for acid bath 1 or more per class
Porcelain crucible and cover 1 per student
Crucible tongs 1 per student
Ring stand with ring 1 per student
Clay triangle 1 per student
Pasteur pipet and bulb or dropper 1 per student
Blue litmus paper 1 piece per student
Bunsen burner 1 per student
Lighter for burner 1 per 1-4 students
Analytical balance (4 decimal places) 4-5 per room
Answers to Pre-Laboratory Questions
1. If a hydrate of the formula MCly·xH2O decomposes when heated to produce HCl, what change
would you expect to occur when a piece of blue litmus paper is held in the path of the vapor
released? Explain.
The blue litmus paper should turn red as blue litmus paper turns red in the presence of acid and
HCl is hydrochloric acid.
Loading page 25...
Experiment 6: Hydrates
13
2. After 0.6523 g of CoCl2·6H2O is heated, the residue has a mass of 0.3423 g. Calculate the % H2O
in the hydrate. What is the formula of the hydrate?
0.6523 g total − 0.3423 g CoCl2 = 0.3100 g H2O
0.3100 g H2O/0.6523 g total × 100% = 47.52 % H2O
0.3100 g H2O/18.02 g·mol−1 = 0.01720 mol H2O
0.3423 g CoCl2/129.83 g·mol−1 = 0.002637 mol CoCl2
0.01720 mol H2O/0.002637 mol CoCl2 = 6.523
Formula is approx. CoCl2·6.5 H2O
3. What safety precautions are necessary in this experiment?
Nitric acid is a strong acid. Be careful and wear gloves and goggles; lab coats are a good
suggestion. Immediately wash any skin or clothing that comes in contact. Wash surfaces that
come in contact so that someone else is not exposed accidentally. Have appropriate spill kit
nearby.
4. CoCl2 is often used in hygrometers. Search the Internet to determine why. How does this relate to
this experiment?
Hygrometer indicates relative humidity,
CoCl2 is blue. As it picks up water, it forms CoCl2·6H2O which is pink.
See, for example, http://wow.osu.edu/experiments/weather/humiditymonitor.html.
13
2. After 0.6523 g of CoCl2·6H2O is heated, the residue has a mass of 0.3423 g. Calculate the % H2O
in the hydrate. What is the formula of the hydrate?
0.6523 g total − 0.3423 g CoCl2 = 0.3100 g H2O
0.3100 g H2O/0.6523 g total × 100% = 47.52 % H2O
0.3100 g H2O/18.02 g·mol−1 = 0.01720 mol H2O
0.3423 g CoCl2/129.83 g·mol−1 = 0.002637 mol CoCl2
0.01720 mol H2O/0.002637 mol CoCl2 = 6.523
Formula is approx. CoCl2·6.5 H2O
3. What safety precautions are necessary in this experiment?
Nitric acid is a strong acid. Be careful and wear gloves and goggles; lab coats are a good
suggestion. Immediately wash any skin or clothing that comes in contact. Wash surfaces that
come in contact so that someone else is not exposed accidentally. Have appropriate spill kit
nearby.
4. CoCl2 is often used in hygrometers. Search the Internet to determine why. How does this relate to
this experiment?
Hygrometer indicates relative humidity,
CoCl2 is blue. As it picks up water, it forms CoCl2·6H2O which is pink.
See, for example, http://wow.osu.edu/experiments/weather/humiditymonitor.html.
Loading page 26...
14
Experiment 7
Gas Laws
For the Instructor
Note that you will need to find an appropriate space in your facility (balcony, stairwell, etc.) where
one can make a measurement at the appropriate height (between 30 and 40 feet). The tygon tubing can
be sealed at one end by plugging with a rubber stopper. We have used filling the tubing as an inquiry-
based exercise; thus, the procedure for this experiment is not spelled out in the lab procedure for the
students. Many groups independently find our best solution – a pipet bulb can be used to set up a
siphon, pulling water from the bucket through the tubing, followed by sealing the end quickly. The
filled tubing should be kept in the bucket to prevent air from getting in until the barometer reading is
attempted. The local barometric pressure can be obtained from any number of sources. For example, a
convenient source is www.weatherchannel.com; just enter a zip code.
For the second part of the experiment, we have found that driving a nail halfway through the #9
rubber stopper and then removing it makes a hole suitable to insert the syringe and get an excellent
seal. The holes should be made in advance, not by the students in the lab, to avoid getting smashed
fingers. The syringe should have a Luer-slip tip.
Necessary Equipment – 24 student
20-L or larger bucket 1-2
40 feet tygon tubing – ¼ inch diameter 1-2
Stopper (size 000) 1-2
Food coloring
Meter stick or tape measurer 1 per group
Pipet bulb 1 per group
Ring stand 1 per group
Clamp 1 per group
50-mL plastic syringe 1 per group
#9 rubber stopper 1 per group
Glycerin
Textbooks 4 per group
Balance (capable of measuring kg quantities) 1
Experiment 7
Gas Laws
For the Instructor
Note that you will need to find an appropriate space in your facility (balcony, stairwell, etc.) where
one can make a measurement at the appropriate height (between 30 and 40 feet). The tygon tubing can
be sealed at one end by plugging with a rubber stopper. We have used filling the tubing as an inquiry-
based exercise; thus, the procedure for this experiment is not spelled out in the lab procedure for the
students. Many groups independently find our best solution – a pipet bulb can be used to set up a
siphon, pulling water from the bucket through the tubing, followed by sealing the end quickly. The
filled tubing should be kept in the bucket to prevent air from getting in until the barometer reading is
attempted. The local barometric pressure can be obtained from any number of sources. For example, a
convenient source is www.weatherchannel.com; just enter a zip code.
For the second part of the experiment, we have found that driving a nail halfway through the #9
rubber stopper and then removing it makes a hole suitable to insert the syringe and get an excellent
seal. The holes should be made in advance, not by the students in the lab, to avoid getting smashed
fingers. The syringe should have a Luer-slip tip.
Necessary Equipment – 24 student
20-L or larger bucket 1-2
40 feet tygon tubing – ¼ inch diameter 1-2
Stopper (size 000) 1-2
Food coloring
Meter stick or tape measurer 1 per group
Pipet bulb 1 per group
Ring stand 1 per group
Clamp 1 per group
50-mL plastic syringe 1 per group
#9 rubber stopper 1 per group
Glycerin
Textbooks 4 per group
Balance (capable of measuring kg quantities) 1
Loading page 27...
Experiment 7: Gas Laws
15
Answers to Pre-Laboratory Questions
1. Look up the atmospheric (or barometric pressure) in your area in the newspaper, on television, or
another news outlet. What are the units used? Convert to mm Hg. Convert to mm H2O.
30.07 inches Hg 2.54 cm/in 10 mm/cm = 762 mm Hg
762 mm Hg 13.5340 g·ml−1/0.99707 g·ml−1 = 1.03 104 mm H2O
2. Should atmospheric pressure increase or decrease as one goes from the beach to the mountains?
Explain.
Decrease, as less of the earth’s atmosphere above.
3. If the column of water in the water barometer rose to a height of 35 feet, what would the
atmospheric pressure be in mmHg?
35 ft 12 in/ft 2.54 cm/in 10 mm/cm = 1.1 104 mm water
1.1 104 mm 0.99707 g·ml−1/ 13.5340 g·ml−1 = 8.1 102 mm Hg
4. After you set up your apparatus for part two of the experiment, your group begins to add the
textbooks to the plunger. It appears that the plunger continues to drop with every added book and
does not return to its original place after the books are removed. What could be possible sources
of error for this experimental reaction? Be specific and give at least two possible reasons.
1) Syringe is leaking – make sure firm seal with tip in stopper and piston in syringe
2) Piston not sliding freely – lubricate as described.
15
Answers to Pre-Laboratory Questions
1. Look up the atmospheric (or barometric pressure) in your area in the newspaper, on television, or
another news outlet. What are the units used? Convert to mm Hg. Convert to mm H2O.
30.07 inches Hg 2.54 cm/in 10 mm/cm = 762 mm Hg
762 mm Hg 13.5340 g·ml−1/0.99707 g·ml−1 = 1.03 104 mm H2O
2. Should atmospheric pressure increase or decrease as one goes from the beach to the mountains?
Explain.
Decrease, as less of the earth’s atmosphere above.
3. If the column of water in the water barometer rose to a height of 35 feet, what would the
atmospheric pressure be in mmHg?
35 ft 12 in/ft 2.54 cm/in 10 mm/cm = 1.1 104 mm water
1.1 104 mm 0.99707 g·ml−1/ 13.5340 g·ml−1 = 8.1 102 mm Hg
4. After you set up your apparatus for part two of the experiment, your group begins to add the
textbooks to the plunger. It appears that the plunger continues to drop with every added book and
does not return to its original place after the books are removed. What could be possible sources
of error for this experimental reaction? Be specific and give at least two possible reasons.
1) Syringe is leaking – make sure firm seal with tip in stopper and piston in syringe
2) Piston not sliding freely – lubricate as described.
Loading page 28...
16
Experiment 8
Styrofoam Cup Calorimetry: Atomic Weights
For the instructor
The results of this experiment are designed to be used in conjunction with those of experiment 5. The
experiment can be performed individually; or to reduce time, samples of the metals can be divided
among members of groups. Normally, individuals or groups can each only make measurements on at
most three metals in a single lab period. A paper towel, folded to make it thicker, can be placed
around the thermometer at the point where it is clamped to help keep the thermometer in place by the
clamp; we find this preferable to a one-hole rubber stopper (as students often snap off thermometers
attempting to insert them into rubber stoppers). The thermometer is clamped in place primarily to
keep it from tipping over the calorimeter. If a stirring bar is used, the thermometer should be placed
off center, leaving room for the stir bar to turn.
Preparation Information – 24 students
The mass of the metal pieces should be approximately 3-5 grams.
Manganese ~1 kg
Chromium ~1 kg
Iron ~1 kg
Zinc ~1 kg
Cadmium ~1 kg
Tin ~1 kg
Necessary Equipment – 24 students
Weigh boats
Paper towels
Styrofoam cup 2 per person
Lid for cup (with hole for thermometer)* 1 per person
Thermometer 2 per person
Ring stand 1 per person
Utility clamp 1 per person
Metal wire or stirring bar 1 per person
Magnetic stirrer 1 per person (optional)
400-mL beaker 1 per person
250-mL beaker 1 per person
Tongs 1 per person
100-mL graduated cylinder 1 per person
Test tube 1 per person
Test tube holder 1 per person
Balances 4-5 per room
*A second tiny hole will be needed if stirring is done with a piece of wire.
Experiment 8
Styrofoam Cup Calorimetry: Atomic Weights
For the instructor
The results of this experiment are designed to be used in conjunction with those of experiment 5. The
experiment can be performed individually; or to reduce time, samples of the metals can be divided
among members of groups. Normally, individuals or groups can each only make measurements on at
most three metals in a single lab period. A paper towel, folded to make it thicker, can be placed
around the thermometer at the point where it is clamped to help keep the thermometer in place by the
clamp; we find this preferable to a one-hole rubber stopper (as students often snap off thermometers
attempting to insert them into rubber stoppers). The thermometer is clamped in place primarily to
keep it from tipping over the calorimeter. If a stirring bar is used, the thermometer should be placed
off center, leaving room for the stir bar to turn.
Preparation Information – 24 students
The mass of the metal pieces should be approximately 3-5 grams.
Manganese ~1 kg
Chromium ~1 kg
Iron ~1 kg
Zinc ~1 kg
Cadmium ~1 kg
Tin ~1 kg
Necessary Equipment – 24 students
Weigh boats
Paper towels
Styrofoam cup 2 per person
Lid for cup (with hole for thermometer)* 1 per person
Thermometer 2 per person
Ring stand 1 per person
Utility clamp 1 per person
Metal wire or stirring bar 1 per person
Magnetic stirrer 1 per person (optional)
400-mL beaker 1 per person
250-mL beaker 1 per person
Tongs 1 per person
100-mL graduated cylinder 1 per person
Test tube 1 per person
Test tube holder 1 per person
Balances 4-5 per room
*A second tiny hole will be needed if stirring is done with a piece of wire.
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Experiment 8: Styrofoam Cup Calorimetry: Atomic Weights
17
Answers to Pre-Laboratory Questions
1. Find and report literature values for the specific heats of the metals used in this experiment at
room temperature.
Cr – 0.107 cal·g−1·K−1
Mn – 0.114
Fe – 0.106
Zn – 0.092
Cd – 0.0555
Sn – 0.053
From Chemical Rubber Handbook
2. Compare the specific heats of the metals with their atomic weights (i.e., molar masses). Do you
see any trends? Make a plot to show this relationship. What does the plot reveal?
Inversely related. Slope is negative of constant of Eqn. 1. For this plot of these few metals, the
value is ~8.7.Atomic Weight
40 60 80 100 120 140
specific heat
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.11
0.12
17
Answers to Pre-Laboratory Questions
1. Find and report literature values for the specific heats of the metals used in this experiment at
room temperature.
Cr – 0.107 cal·g−1·K−1
Mn – 0.114
Fe – 0.106
Zn – 0.092
Cd – 0.0555
Sn – 0.053
From Chemical Rubber Handbook
2. Compare the specific heats of the metals with their atomic weights (i.e., molar masses). Do you
see any trends? Make a plot to show this relationship. What does the plot reveal?
Inversely related. Slope is negative of constant of Eqn. 1. For this plot of these few metals, the
value is ~8.7.Atomic Weight
40 60 80 100 120 140
specific heat
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.11
0.12
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Experiment 8: Styrofoam Cup Calorimetry: Atomic Weights
18
3. If you are performing the calibration step of this experiment and you begin with 50 g of water at
20 °C and 50 g of water at 80 °C. After adding the two in your calorimeter setup and following the
procedure outlined in the experiment, you determine the temperature of the mixed solutions to be
45 °C. What is the heat capacity of the calorimeter?
Use Eqn. 4 and assume room temperature is 25 °C:
-S.H.warm water masswarm water Twarm water =
S.H.cool water × masscool water Tcool water + Ccalorimeter Tcalorimeter
-1.00 cal/g·K 50 g (45 °C − 80 °C) = 1.00 cal/g·K 50 g (45 °C − 20 °C) +
Ccalorimeter (45 °C − 25 °C)
Ccalorimeter = 25 cal/K
18
3. If you are performing the calibration step of this experiment and you begin with 50 g of water at
20 °C and 50 g of water at 80 °C. After adding the two in your calorimeter setup and following the
procedure outlined in the experiment, you determine the temperature of the mixed solutions to be
45 °C. What is the heat capacity of the calorimeter?
Use Eqn. 4 and assume room temperature is 25 °C:
-S.H.warm water masswarm water Twarm water =
S.H.cool water × masscool water Tcool water + Ccalorimeter Tcalorimeter
-1.00 cal/g·K 50 g (45 °C − 80 °C) = 1.00 cal/g·K 50 g (45 °C − 20 °C) +
Ccalorimeter (45 °C − 25 °C)
Ccalorimeter = 25 cal/K
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Chemistry