Laboratory Manual
for
General Chemistry 1411
David Carter
Kevin A. Boudreaux
Nick Flynn
Joe Velasquez, III
ANGELO STATE UNIVERSITY
Department of Chemistry and Biochemistry
San Angelo, Texas 76909
FALL, 2010
2
While reading a textbook of chemistry I came upon the statement, “nitric acid acts
upon copper.” I was getting tired of reading such absurd stuff and I was
determined to see what this meant. Copper was more or less familiar to me, for
copper cents were then in use. I had seen a bottle marked nitric acid on a table in
the doctor’s office where I was then “doing time.” I did not know its peculiarities,
but the spirit of adventure was upon me. Having nitric acid and copper, I had only
to learn what the words “act upon” meant. The statement “nitric acid acts upon
copper” would be something more than mere words. All was still. In the interest
of knowledge I was even willing to sacrifice one of the few copper cents then in
my possession. I put one of them on the table, opened the bottle marked nitric
acid, poured some of the liquid on the copper and prepared to make an
observation. But what was this wonderful thing which I beheld? The cent was
already changed and it was no small change either. A green-blue liquid foamed
and fumed over the cent and over the table. The air in the neighborhood of the
performance became colored dark red. A great colored cloud arose. This was
disagreeable and suffocating. How should I stop this? I tried to get rid of the
objectionable mess by picking it up and throwing it out of the window. I learned
another fact. Nitric acid not only acts upon copper, but it acts upon fingers. The
pain led to another unpremeditated experiment. I drew my fingers across my
trousers and another fact was discovered. Nitric acid acts upon trousers. Taking
everything into consideration, that was the most impressive experiment and
relatively probably the most costly experiment I have ever performed. I tell of it
even now with interest. It was a revelation to me. It resulted in a desire on my part
to learn more about that remarkable kind of action. Plainly, the only way to learn
about it was to see its results, to experiment, to work in a laboratory.
Ira Remsen, quoted in F. H. Getman, The Life of Ira Remsen (1940)1
1
Frederick Hutton Getman, The Life of Ira Remsen. Easton: Journal of Chemical Education, 1940, p. 9-10.
3
Table of Contents
All I Really Need To Know I Learned in a Chemistry Lab .............................................................5
Foreword ..........................................................................................................................................7
Laboratory Equipment .....................................................................................................................7
Introduction and Review of Some Important Concepts: ...........................................................9
I. Significant Figures .............................................................................................................11
II. Scientific Notation .............................................................................................................15
III. Units of Measure ................................................................................................................19
IV. Dimensional Analysis ........................................................................................................22
V. Accuracy and Precision; Standard Deviations ...................................................................25
VI. Properties ...........................................................................................................................28
Experiments: ................................................................................................................................31
Measuring Mass, Length, Volume and Density.................................................................33
Determining the Concentration of Sugar in a Commercial Beverage ...............................53
Stoichiometry I: Determining the Percent Composition of Ammonium
Chloride, Salt, and Sand in a Mixture ...........................................................................63
Stoichiometry II: Molar Mass ...........................................................................................69
Stoichiometry III: Determining the Percent Composition
of Potassium Chlorate in a Mixture ..............................................................................77
Stoichiometry IV: Titration of Vinegar ............................................................................85
Specific Heat Capacity.......................................................................................................93
Chemical Reactions I: Some Chemical Reactions Involving Oxygen............................103
Chemical Reactions II: Reactions of Ions in Solution ....................................................121
The Gas Laws ..................................................................................................................139
The Gas Laws: Finding the Molar Mass of Oxygen .......................................................151
Heats of Reaction: Hess’s Law .......................................................................................157
Titration of Hydrogen Peroxide .......................................................................................169
Limiting Reactants ...........................................................................................................179
Paper Chromatography ....................................................................................................193
Empirical Formula by Microanalysis...............................................................................199
4
Appendices: ................................................................................................................................205
I. Conversion Factors ..........................................................................................................207
II. Physical Constants ...........................................................................................................213
III. Formula Writing and Nomenclature ................................................................................217
IV. Graphing in Microsoft Excel 2007 ..................................................................................227
References ........................................................................................................................233
Periodic Table of the Elements ............................................................................ back cover
5
ALL I REALLY NEED TO KNOW
I LEARNED IN A CHEMISTRY LAB
The following rules are to be observed in this lab at all times:
Eyewear: The PRIME DIRECTIVE in any Chemistry lab is:
WEAR GOGGLES AT ALL TIMES!!!!!
Lab Dress: Beginning on the first day of lab, everyone MUST have approved goggles,
long-sleeved shirts which cover the midriff, long pants, and shoes with
closed toes and heels (no sandals, slides, etc.). (Basically, you should have as
little exposed skin as possible.) Anyone not wearing the appropriate attire will
not be allowed into lab.
Fires: Most organic materials — including you, your hair, and your clothing — are
flammable. Know the location of the safety showers, fire extinguishers, and fire
blankets.
Floods: Be careful with drain hoses and leaky faucets.
Injuries: Blood is always a sure sign of bad laboratory technique. Check all glassware for
cracks, sharp edges, or star cracks before using it.
Any injury no matter how trivial, should be reported to the lab instructor.
Spills: Notify the lab instructor of any spills which occur during the lab. Minor spills
can be cleaned by students, but do not try to clean up reagent or solvent spills
yourself; some of these materials require special care in their disposal.
Clean up any spills immediately.
Behavior: Do not eat, drink, smoke, or chew gum in the lab.
Work only at your assigned desk.
Do not perform experiments other than those which are scheduled for that day.
No horseplay will be tolerated.
Wastes: Throw away trash in the appropriate containers.
Follow the directions of your instructor for discarding wastes from that day’s
work. These instructions must be followed carefully; disposing of chemical
wastes in the wrong way may result in dangerous reactions (or at least a foulsmelling lab — or a foul-smelling chemist). Always ask if you’re unsure.
6
Broken glass should be discarded in the designated waste containers. NEVER
throw glass away in the trash cans!
Reagents: Do not move reagent bottles from their assigned place.
Always recap reagent bottles! Some reagents decompose when exposed to the
atmosphere for a period of time.
Do not stick anything into the reagent bottles. If a spatula is provided for that
purpose, be sure that the same spatula is used in the same bottle.
If you pour out or weigh out too much of any reagent or solvent from the bottle,
do NOT put the excess back in the bottle. This will risk introducing
contaminants into the main supply of the reagent. Unused or excess reagents
should be disposed of in the appropriate waste container.
When an experiment calls for water, use deionized water provided in the wash
bottles on the lab benches unless the directions specifically call for tap water.
USE ONLY TAP WATER IN HOT WATER BATHS!
Never add water to acid!
Never add boiling chips or activated carbon to hot liquids!
Fume Hoods: Fume hoods are used when a procedure may produce smoke or strong odors.
Keep the fume hoods clean! Do not leave weighing paper lying around in the
hood after you’re finished with it.
Balances: Keep the balances clean. Immediately clean up any chemicals which are
spilled on the balances, or around the balance area.
Do not leave stray pieces of paper or glassware around the balances.
Equipment: Bunsen burners, ring stands, clamps and O-rings, and buret clamps are available
on the side shelves. At the end of the laboratory period, clean the desk space
and return burners, clamps, and ring stands to their assigned spaces.
Glassware: Hot glass looks exactly like cold glass.
Check all glassware for cracks, sharp edges, or star cracks before using it. (I
know I said this already, but it bears repeating.)
Cleaning up: Clean up your bench before leaving.
Be sure that the gas, water, and electric hotplate/stirrers are turned off. Return
all glassware and hardware to their respective drawers, and return ringstands to
the shelves on the side of the lab.
Wash your hands after leaving the laboratory, or at any time you think that
chemicals may have come in contact with your hands.
7
Foreword
The CHEM 1411 General Chemistry laboratory class accompanies the CHEM 1411
General Chemistry lecture class. The grades for these classes are combined to give one fourcredit grade for the course.
This laboratory sequence is designed to illustrate some of the principles involved in
performing scientific measurements, handling chemicals, and performing chemistry experiments.
In some cases, the experiments in the lab are designed to introduce you to concepts before you
cover them in the lecture course, and in some cases, the experiments will reinforce concepts
already covered in the lecture course.
Pay attention to the directions that your lab instructor gives you concerning the
assignments which must be completed before the lab. In many cases, there will be Pre-Lab
Assignments that must be done on the computer before you can participate in that day’s lab.
Laboratory Equipment
The following is a list of all of the glassware that should be found in the Glassware and
Hardware drawers:
Equipment in Glassware Drawer
Glassware Drawer
Beaker, 100 mL (1)
Beaker, 150 mL (1)
Beaker, 250 mL (1)
Beaker, 400 mL (1)
Crucible with lid (2)
Erlenmeyer Flask, 250 mL (2)
Evaporating Dish (1)
Funnel, Glass (1)
Graduated Cylinder, 50 mL (1)
Split Rubber Stopper (1)
Stirring Rod (1)
Thermometer (1)
Watch Glass (1)
Hardware Drawer
Burner, Bunsen (1)
Clamp, Buret (1)
Clamp, Ring (1)
Clamp, Test Tube (1)
Clay Triangle (1)
Crucible Tongs (1)
Hose, Gas (1)
Ruler, Plastic, 6”
Scoopula (1)
Test Tube Holder (1)
Wire Gauze (1)
See Figure 1 for an illustration of some of this glassware and equipment. (The glassware
on this figure is not drawn to scale.) Other equipment that you will need during this lab will be
provided as it is needed.
8
Beaker
Erlenmeyer Flask
Evaporating Dish
Funnel, Glass
Graduated Cylinder
Stirring Rod
Thermometer
Watch Glass
Burner, Bunsen
Clamp, Buret
Clamp, Ring
Clamp, Test Tube
Clay Triangle
Crucible with lid
Crucible Tongs
Split Rubber Stopper
Hose, Gas
Scoopula
Test Tube Holder
Wire Gauze
Figure 1. Some typical lab glassware and hardware.