Contents
Preface: Introduction and Description of Changes for This Edition v
Experiments
1. The Determination of Mass ........................................................................................................ 1
2. The Use of Volumetric Glassware ............................................................................................. 3
3. Density Determinations .............................................................................................................. 5
4. The Determination of Boiling Point .......................................................................................... 7
5. Recrystallization and Melting Point Determination ................................................................... 9
6. The Solubility of a Salt ........................................................................................................... 11
7. Identification of A Substance .................................................................................................. 13
8. Resolution of Mixtures 1: Filtration and Distillation .............................................................. 15
9. Resolution of Mixtures 2: Chromatography ............................................................................ 17
10. Stoichiometry 1: Limiting Reactant ........................................................................................ 20
11. Stoichiometry 2: Stoichiometry of an Iron(III)-Phenol Reaction ........................................... 22
12. Composition 1: Percentage Composition and the Empirical Formula of Magnesium Oxide .. 24
13. Composition 2: Hydrates and Thermal Decomposition ........................................................... 26
14. Preparation and Properties of Hydrogen and Oxygen Gases ................................................... 29
15. Molar Volume and The Universal Gas Constant ..................................................................... 31
16. Gas Laws 2: Graham’s Law ..................................................................................................... 33
17. Calorimetry .............................................................................................................................. 35
18. Hess’s Law ............................................................................................................................... 37
19. Spectroscopy 1: Spectra of Atomic Hydrogen and Nitrogen ................................................... 39
20. Spectroscopy 2: Emission Spectra of Metallic Elements ......................................................... 41
21. Molecular Shapes and Structures ............................................................................................. 43
22. Properties of Some Representative Elements .......................................................................... 45
23. Classification of Chemical Reactions ...................................................................................... 47
24. Colligative Properties 1: Freezing Point Depression and the Determination of Molar Mass .. 50
25. Colligative Properties 2: Osmosis and Dialysis ....................................................................... 52
26. Rates of Chemical Reactions .................................................................................................... 54
27. Chemical Equilibrium 1: Titrimetric Determination of An Equilibrium Constant .................. 56
28. Chemical Equilibrium 2: Spectrophotometric Determination of An Equilibrium Constant.... 58
29. Chemical Equilibrium 3: Stresses Applied to Equilibrium Systems ....................................... 60
30. The Solubility Product Constant of Calcium Iodate ................................................................ 62
31. Acids, Bases, and Buffered Systems ........................................................................................ 64
iii
,32. Acid–Base Titrations 1: Analysis of an Unknown Acid Sample ............................................ 67
33. Acid–Base Titrations 2: Evaluation of Commercial Antacid Tablets ...................................... 69
34. The Determination of Calcium in Calcium Supplements ........................................................ 71
35. Determination of Iron by Redox Titration .............................................................................. 73
36. Determination of Vitamin C in Fruit Juices ............................................................................. 75
37. Electrochemistry 1: Chemical Cells ......................................................................................... 77
38. Electrochemistry 2: Electrolysis .............................................................................................. 79
39. Gravimetric Analysis 1: Determination of Chloride Ion.......................................................... 81
40. Gravimetric Analysis 2: Determination of Sulfate Ion ............................................................ 83
41. Preparation of a Coordination Complex of Copper(II) ........................................................... 85
42. Inorganic Preparations 1: Synthesis of Sodium Thiosulfate Pentahydrate .............................. 87
43. Inorganic Preparations 2: Preparation of Sodium Hydrogen Carbonate .................................. 89
44. Qualitative Analysis of Organic Compounds .......................................................................... 91
45. Organic Chemical Compounds ................................................................................................ 94
46. Ester Derivatives of Salicylic Acid .......................................................................................... 97
47. Preparation of Fragrant Esters .................................................................................................. 99
48. Proteins ................................................................................................................................... 101
49. Enzymes ................................................................................................................................. 103
50. Polymeric Substances 1: Amorphous Sulfur.......................................................................... 105
51. Polymeric Substances 2: Preparation of Nylon ...................................................................... 107
52. Qualitative Analysis of Selected Cations and Anions............................................................ 109
iv
,Preface
The person responsible for the administration of a general chemistry laboratory program is often the
hardest working member of his or her department. There is an endless number of details associated with
this job: scheduling laboratory experiments, scheduling lab instructors, ordering supplies, preparing
reagents, grading lab reports, and so on, ad infinitum. The reader perhaps can tell that this is the author’s
own occupation!
This Instructor’s Resource Manual is intended to make the job as painless and as rewarding as possible.
The notes for each experiment are divided into four parts, described below. In particular, detailed recipes
are provided for the preparation of the many reagents required, which in itself will save the instructor
much time and effort.
Part A of each set of notes is a general introduction to each experiment from the instructor’s point of
view, illustrating what students are expected to learn from the experiment, and oftentimes pointing out
pitfalls in the experiment. Specific suggestions for specialized equipment, or possible modification of the
experiment, are given for many experiments.
The materials required for each experiment are given as Part B of the notes. In particular, instructions are
given for the preparation of the many solutions required for the laboratory experiments. Since a school
may be running several sections of laboratory in different rooms at the same time, instructions are most
commonly given in terms of preparing one liter of a particular solution, even though the experiment may
call for more or less than this as actually performed. One liter was chosen as a standard amount, since it
should be relatively easy from this to calculate the actual amounts of solute/solvent needed for your
particular situation. For some special reagents, requiring more complicated preparation, instructions are
given for the specific amount required for the experiment as performed. The instructor should also take
into account that in some instances a given substance may be available in both a hydrated and an
anhydrous form: It is always specified in the notes which form the amounts given refer to.
Part C of these notes contains answers to the Pre-Laboratory Questions, whereas Part D has the answers
to the Post-Laboratory Questions. Questions requiring students to look up a definition or explanation are
keyed as far as possible to sections of the Zumdahl text, with occasional reference to Wikipedia (our
students’ favorite resource). Questions involving the looking up of data are generally keyed to the CRC
Handbook of Chemistry and Physics online edition.
From the New Author:
Having taught AP Chemistry for over 25 years, as well as both introductory chemistry and general
chemistry at community colleges, I am most excited to be taking over as lead author of Experimental
Chemistry. More about that under “Description of Changes For The 10th edition.” As I assume the
responsibility as James F. Hall’s successor (‘replacement’, never), I will repeat his promise to the users of
This Manual: Comments, criticism, and suggestions are always welcome from users of Experimental
Chemistry and this Instructor’s Resource Manual. I always appreciate your help in improving these
materials for your students.
John G. Little
jglittle@pacbell.net
v
, Description of Changes for the 10th edition of Experimental Chemistry
In this the 10th edition of Experimental Chemistry, I have attempted to achieve three goals. First, the
number of labs has been reduced in an effort to focus on those skills that students in a general chemistry
course need to master. For that reason, some experiments that our students would have done either in a
good high school course or in a post-secondary introductory course have been eliminated. In a couple of
cases, two separate, relatively simple experiments were merged into one long activity, on the assumption
that doing so provided the individual instructor with some flexibility as to which parts to assign and
which to bypass. See the experiment, “Resolution of Mixtures 2: Chromatography,” for example. The
familiar experiment on hydrates has been expanded significantly to extend the concept of heating to
constant mass and to illustrate how the formula of a compound may be determined from decomposition
data.
The second objective was to eliminate insofar as possible the use of reagents known to be highly toxic
and/or carcinogenic or mutagenic. Any direct use of mercury or hexavalent chromium, for example, has
been eliminated. This means that the Charles’ Law experiment is gone, as is the use of chromate indicator
in a titrimetric chloride analysis. Due to the toxicity of reagents, including chromates and thioacetamide,
the classical quantitative cation analysis schemes have been replaced by an expanded experiment based
on the analysis of selected anions, merged with identification of the cations in the alkaline earth family.
For those who still want to have students learn the techniques of cation qualitative analysis, and who are
not constrained from using the reagents called for in those experiments, they are available online, in
unchanged form.
In addition to the two labs on spectroscopy of elements, which have been carried over in their original
form from previous editions, I have added an activity involving calculation of the energy changes
involved in transitions between allowed atomic energy levels. While not in the printed manual, this
activity is available online, as “Chapter 7 Exercise – The Atomic Spectra of Hydrogen and Hydrogen-like
Atoms.”
The reluctance to use hexavalent chromium has also led to replacement of the subject of an experimental
determination of a Ksp value. Instead of using a chromium(VI) indicator for the titration of silver acetate,
the new version, Experiment 30 – “The Solubility Product of Calcium Iodate.”
Finally, it is my intent that figures more closely represent what today’s students can expect to encounter.
The photo of a modern electronic pH meter in Experiment 14 is a good example of that, as is the fact that
in Experiment 1, “Mass Determinations,” the three balances shown are the traditional triple-beam
mechanical balance, the top-loading electronic balance, and an analytical balance.
As always, corrections, suggestions, and general comments are most welcome, and I’ll be happy to
respond to messages sent to the address below.
John Little
jglittle@pacbell.net
vi
