Chapter 1. Introduction

What you take away from an experience depends on how you approach it and what you hope to get out of it.

If you’re a hobbyist, no problem. Simply read the book from start to finish and do the labs in the order they’re presented. You’ll have a lot of fun and learn a lot about chemistry along the way.

If you’re a home school student or a public school student who wants a laboratory chemistry course to supplement and enhance a lecture-based high school chemistry course, you’ll need to do a bit more planning. The lab sessions in this book cover at least two years’ worth of high school chemistry lab work, including a full set of labs appropriate for a first-year chemistry lab course and a second group of labs appropriate for a second-year or AP (Advanced Placement) chemistry lab course.

The laboratory sessions in this book are organized topically by chapter, but their order may not correspond to the order in which topics are covered in your chemistry text book. That’s not really a problem, because you can do these labs in whatever order matches that of your chemistry text. Choosing which labs to do is another matter.

Look it Up

Because this book focuses on chemistry lab work rather than chemistry theory, if you aren’t using this book in conjunction with a chemistry textbook there may be times when you come across a term that’s unfamiliar to you. Usually, the term will be clear from context. If it isn’t clear, don’t guess. Look it up, either on-line or in a good general chemistry textbook.

One good general chemistry textbook is Chemistry, The Central Science (Brown, et al., Prentice Hall, 2002), but there are many others available. Chemistry textbooks are often available very inexpensively in used bookstores, and even a copy that’s several editions out of date is fine. Chemistry textbooks are frequently updated with very minor changes, but even a copy that’s 10 or more years old covers all the fundamentals. General chemistry just doesn’t change much over the years.

Students who will go on to major in college in nonscience disciplines need only a first-year chemistry course with some exposure to basic chemistry lab procedures. For these students, one 60- to 90-minute chemistry lab period per week suffices. The following labs, some of which require two sessions, are a good starting point:

6.1	–	Differential Solubility: Separate Sugar and Sand
6.5	–	Chromatography: Two-Phase Separation of Mixtures (first part only)
7.1	–	Make Up a Molar Solution of a Solid Chemical
8.3	–	Observe the Effects of Osmotic Pressure
9.1	–	Observe a Composition Reaction
9.3	–	Observe a Single-Displacement Reaction
11.1	–	Determine the Effect of Concentration on pH
13.1	–	Observe Le Chatelier’s Principle in Action
14.1	–	Observe the Volume-Pressure Relationship of Gases (Boyle’s Law)
15.1	–	Determine Heat of Solution
15.2	–	Determine the Specific Heat of Ice
16.1	–	Produce Hydrogen and Oxygen by Electrolysis of Water
18.1	–	Observe Some Properties of Colloids and Suspensions
19.1	–	Using Flame Tests to Discriminate Metal Ions
19.2	–	Using Borax Bead Tests to Discriminate Metal Ions

Students who will go on to major in college in science disciplines need a first-year chemistry course with much more exposure to chemistry lab procedures. For these students, allocate two 90-minute to 2-hour chemistry lab periods per week or one 3- to 4-hour lab period. (Regularly scheduled weekend lab sessions, when other classes do not interfere, are often the most suitable time for home school students and the only practical time for public school students.) The following lab sessions are a good starting point:

6.1	–	Differential Solubility: Separate Sugar and Sand
6.2	–	Distillation: Purify Ethanol
6.3	–	Recrystallization: Purify Copper Sulfate
6.4	–	Solvent Extraction
6.5	–	Chromatography: Two-Phase Separation of Mixtures
7.1	–	Make Up a Molar Solution of a Solid Chemical
7.2	–	Make Up a Molal Solution of a Solid Chemical
7.3	–	Make Up a Molar Solution of a Liquid Chemical
7.4	–	Make Up a Mass-to-Volume Percentage Solution
8.1	–	Determine Molar Mass by Boiling Point Elevation
8.2	–	Determine Molar Mass by Freezing Point Depression
8.3	–	Observe the Effects of Osmotic Pressure
9.1	–	Observe a Composition Reaction
9.2	–	Observe a Decomposition Reaction
9.3	–	Observe a Single-Displacement Reaction
9.4	–	Stoichiometry of a Double Displacement Reaction
10.1	–	Reduction of Copper Ore to Copper Metal
10.2	–	Observe the Oxidation States of Manganese
11.1	–	Determine the Effect of Concentration on pH
12.1	–	Determine the Effect of Temperature on Reaction Rate
12.2	–	Determine the Effect of Surface Area on Reaction Rate
12.3	–	Determine the Effect of Concentration on Reaction Rate
13.1	–	Observe Le Chatelier’s Principle in Action
13.2	–	Quantify the Common Ion Effect
14.1	–	Observe the Volume-Pressure Relationship of Gases (Boyle’s Law)
14.2	–	Observe the Volume-Temperature Relationship of Gases (Charles’s Law)
14.3	–	Observe the Pressure-Temperature Relationship of Gases (Gay-Lussac’s Law)
15.1	–	Determine Heat of Solution
15.2	–	Determine the Specific Heat of Ice
15.3	–	Determine the Specific Heat of a Metal
16.1	–	Produce Hydrogen and Oxygen by Electrolysis of Water
18.1	–	Observe Some Properties of Colloids and Suspensions
18.2	–	Produce Firefighting Foam
18.3	–	Prepare a Gelled Sol
19.1	–	Using Flame Tests to Discriminate Metal Ions
19.2	–	Using Borax Bead Tests to Discriminate Metal Ions

A Note on the AP Chemistry Exam

While we were discussing the AP Chemistry exam, Dr. Paul Jones made a profound comment that is worth serious consideration. Many of Paul’s first-year organic chemistry students pass the AP Chemistry exam with a 4 or 5 score and skip first-year college general chemistry. Paul thinks that’s a mistake, because almost none of those students actually got the full equivalent of first-year college general chemistry in their AP courses.

As Paul said, it’s fine for a history major to take the AP Chemistry exam and test out of taking a first-year college chemistry course, and it’s fine for a chemistry major to take the AP History exam and test out of taking a first-year college history course. But the history major shouldn’t test out of taking the first-year history course, and the chemistry (or other science) major shouldn’t test out of taking the first-year chemistry course.

That’s not to say that future chemistry (or physics, biology, or other hard science) majors shouldn’t take the AP Chemistry course itself. Worst case, by taking the intro course in your major even though you already have the AP course under your belt, you end up with an easy A, impress your professors, and hit the ground running.

For second-year (AP) chemistry students, allocate at least two 2-hour chemistry lab periods per week or one 4-hour lab period. The following lab sessions (which assume that the preceding group of labs has been completed in a first-year course) are a good starting point:

6.6	–	Determine the Formula of a Hydrate
7.5	–	Determine Concentration of a Solution by Visual Colorimetry
11.2	–	Determine the pH of Aqueous Salt Solutions
11.3	–	Observe the Characteristics of a Buffer Solution
11.4	–	Standardize a Hydrochloric Acid Solution by Titration
12.4	–	Determine the Effect of a Catalyst on Reaction Rate
13.3	–	Determine a Solubility Product Constant
14.4	–	Use the Ideal Gas Law to Determine the Percentage of Acetic Acid in Vinegar
14.5	–	Determine Molar Mass from Vapor Density
15.4	–	Determine the Enthalpy Change of a Reaction
16.2	–	Observe the Electrochemical Oxidation of Iron
16.3	–	Measure Electrode Potentials
16.4	–	Observe Energy Transformation
16.5	–	Build a Voltaic Cell
16.6	–	Build a Battery
17.1	–	Photochemical Reaction of Iodine and Oxalate
19.3	–	Qualitative Analysis of Inorganic Anions
19.4	–	Qualitative Analysis of Inorganic Cations
19.5	–	Qualitative Analysis of Bone
20.1	–	Quantitative Analysis of Vitamin C by Acid-Base Titration
20.2	–	Quantitative Analysis of Chlorine Bleach by Redox Titration
20.3	–	Quantitative Analysis of Seawater
21.1	–	Synthesize Methyl Salicylate from Aspirin
21.2	–	Synthesize Rayon Fiber
22.1	–	Use the Sherlock Holmes Test to Detect Blood
22.2	–	Perform a Presumptive Test for Illicit Drugs
22.3	–	Reveal Latent Fingerprints
22.4	–	Use the Marsh Test to Detect Arsenic or Antimony

Table 1-1 summarizes how the lab sessions in this book map to the experiments recommended by the College Board for the AP Chemistry exam. Note that some of the recommended experiments are completed in the first year and need not be repeated in the second.

Table 1-1. AP Recommended Experiments mapped to laboratory sessions in this book

#	AP Recommended Experiment	#	Corresponding Laboratory Session(s)
1	Determination of the formula of a compound	9.2	Observe a Decomposition Reaction
2	Determination of the percentage of water in a hydrate	6.6	Determine the Formula of a Hydrate
3	Determination of molar mass by vapor density	14.5	Determine Molar Mass from Vapor Density
4	Determination of molar mass by freezing point depression	8.2	Determine Molar Mass by Freezing Point Depression
5	Determination of the molar volume of a gas	14.4	Use the Ideal Gas Law to Determine the Percentage of Acetic Acid in Vinegar
6	Standardization of a solution using a primary standard	11.4	Standardize a Hydrochloric Acid Solution by Titration
7	Determination of concentration by acid-base titration, including a weak acid or weak base	20.1	Quantitative Analysis of Vitamin C by Acid-Base Titration
8	Determination of concentration by oxidation-reduction titration	20.2	Quantitative Analysis of Chlorine Bleach by Redox Titration
9	Determination of mass and mole relationship in a chemical reaction	9.4	Stoichiometry of a Double Displacement Reaction
10	Determination of the equilibrium constant for a chemical reaction	13.3	Determine a Solubility Product Constant
11	Determination of appropriate indicators for various acid-base titrations; pH determination	11.1 11.2	Determine the Effect of Concentration on pH Determine the pH of Aqueous Salt Solutions
12	Determination of the rate of a reaction and its order	12.1 12.2 12.3 12.4	Determine the Effect of Temperature on Reaction Rate Determine the Effect of Surface Area on Reaction Rate Determine the Effect of Concentration on Reaction Rate Determine the Effect of a Catalyst on Reaction Rate
13	Determination of enthalpy change associated with a reaction	15.4	Determine the Enthalpy Change of a Reaction
14	Separation and qualitative analysis of cations and anions	19.3 19.4 19.5	Qualitative Analysis of Inorganic Anions Qualitative Analysis of Inorganic Cations Qualitative Analysis of Bone
15	Synthesis of a coordination compound and its chemical analysis	21.2	Synthesize Rayon Fiber
16	Analytical gravimetric determination	20.3	Quantitative Analysis of Seawater
17	Colorimetric or spectrophotometric analysis	7.5 17.1	Determine Concentration of a Solution by Visual Colorimetry Photochemical Reaction of Iodine and Oxalate
18	Separation by chromatography	6.5	Chromatography: Two-Phase Separation of Mixtures
19	Preparation and properties of buffer solutions	11.3	Observe the Characteristics of a Buffer Solution
20	Determination of electrochemical series	16.1 16.2 16.3	Produce Hydrogen and Oxygen by Electrolysis of Water Observe the Electrochemical Oxidation of Iron Measure Electrode Potentials
21	Measurements using electrochemical cells and electroplating	16.4 16.5 16.6	Observe Energy Transformation Build a Voltaic Cell Build a Battery
22	Synthesis, purification, and analysis of an organic compound	21.1	Synthesize Methyl Salicylate from Aspirin

Maintaining a Laboratory Notebook

A laboratory notebook is a contemporaneous, permanent primary record of the owner’s laboratory work. In real-world corporate and industrial chemistry labs, the lab notebook is often a critically important document, for both scientific and legal reasons. The outcome of zillion-dollar patent lawsuits often hinges on the quality, completeness, and credibility of a lab notebook. Many corporations have detailed procedures that must be followed in maintaining and archiving lab notebooks, and some go so far as to have the individual pages of researchers’ lab notebooks notarized and imaged on a daily or weekly basis.

If you’re just starting to learn about chemistry lab work, keeping a detailed lab notebook may seem to be overkill, but it’s not. Although this book provides tables for recording data and spaces for answering the questions it poses, that’s really for the convenience of hobbyist readers. If you’re using this book to prepare for college chemistry, and particularly if you plan to take the Advanced Placement (AP) Chemistry exam, you should keep a lab notebook. Even if you score a 5 on the AP Chemistry exam, many college and university chemistry departments will not offer you advanced placement unless you can show them a lab notebook that meets their standards.

Laboratory Notebook Guidelines

Use the following guidelines to maintain your laboratory notebook:

• The notebook must be permanently bound. Looseleaf pages are unacceptable. Never tear a page out of the notebook.

• Use permanent ink. Pencil or erasable ink is unacceptable. Erasures are anathema.

• Before you use it, print your name and other contact information on the front of the notebook, as well as the volume number (if applicable) and the date you started using the notebook.

• Number every page, odd and even, at the top outer corner, before you begin using the notebook.

• Reserve the first few pages for a table of contents.

• Begin a new page for each experiment.

• Use only the righthand pages for recording information. The lefthand pages can be used for scratch paper. (If you are lefthanded, you may use the lefthand pages for recording information, but maintain consistency throughout.)

• Record all observations as you make them. Do not trust your memory, even for a minute.

• Print all information legibly, preferably in block letters. Do not write longhand.

• If you make a mistake, draw one line through the erroneous information, leaving it readable. If it is not otherwise obvious, include a short note explaining the reason for the strikethrough. Date and initial the strikethrough.

• Do not leave gaps or whitespace in the notebook. Cross out whitespace if leaving an open place in the notebook is unavoidable. That way, no one can go back in and fill in something that didn’t happen. When you complete an experiment, cross out the whitespace that remains at the bottom of the final page.

• Incorporate computer-generated graphs, charts, printouts, photographs, and similar items by taping or pasting them into the notebook. Date and initial all add-ins.

• Include only procedures that you personally perform and data that you personally observe. If you are working with a lab partner and taking shared responsibility for performing procedures and observing data, note that fact as well as describing who did what and when.

• Remember that the ultimate goal of a laboratory notebook is to provide a permanent record of all the information necessary for someone else to reproduce your experiment and replicate your results. Leave nothing out. Even the smallest, apparently trivial, detail may make the difference.

Laboratory Notebook Format

Use the following general format for recording an experiment in your lab notebook:

Introduction

The following information should be entered before you begin the laboratory session:

• Date

  Enter the date at the top of the page. Use an unambiguous date format, such as 2 September 2008 or September 2, 2008 rather than 2/9/8 or 9/2/8. If the experiment runs more than one day, enter the starting date here and the new date in the procedure/data section at the time you actually begin work on that date.

• Experiment title

  If the experiment is from this or another laboratory manual, use the name from that manual and credit the manual appropriately. For example, “Quantitative Analysis of Chlorine Bleach by Redox Titration (Illustrated Guide to Home Chemistry Experiments, #20.2)”. If the experiment is your own, give it a descriptive title.

• Purpose

  Write one or two sentences that describe the goal of the experiment. For example, “To determine the concentration of chlorine laundry bleach by redox titration using a starch-iodine indicator.”

• Introduction (optional)

  Any preliminary notes, comments, or other information may be entered in a paragraph or two here. For example, if you decided to do this experiment to learn more about something you discovered in another experiment, note that fact here.

• Balanced equations

  Write down balanced equations for all of the reactions involved in the experiment, including, if applicable, changes in oxidation state.

• Chemical information

  Important information about all chemicals used in the experiment, including, if appropriate, physical properties (melting/boiling points, density, etc.), a list of relevant hazards and safety measures from the MSDS (the Material Safety Data Sheet for the chemical), and any special disposal methods required. Include approximate quantities, both in grams and in moles, to give an idea of the scale of the experiment.

• Planned procedure

  A paragraph or two to describe the procedures you expect to follow.

Main body

The following information should be entered as you actually do the experiment:

• Procedure

  Record the procedure you use, step by step, as you actually perform the procedures. Note any departures from your planned procedure and the reasons for them.

• Data

  Record all data and observations as you gather them, inline with your running procedural narrative. Pay attention to significant figures, and include information that speaks to accuracy and precision of the equipment and chemicals you use. For example, if one step involves adding hydrochloric acid to a reaction vessel, it makes a difference if you added 5 mL of 0.1 M hydrochloric acid from a 10 mL graduated cylinder or 5.00 mL of 0.1000 M hydrochloric acid from a 10 mL pipette.

• Sketches

  If your setup is at all unusual, make a sketch of it here. It needn’t be fine art, nor does it need to illustrate common equipment or setups such as a beaker or a filtering setup. The goal is not to make an accurate representation of how the apparatus actually appears on your lab bench, but rather to make it clear how the various components relate to each other. Be sure to clearly label any relevant parts of the set up.

• Calculations

  Include any calculations you make. If you run the same calculation repeatedly on different data sets, one example calculation suffices.

• Table(s)

  If appropriate, construct a table or tables to organize your data. Copy data from your original inline record to the table or tables.

• Graph(s)

  If appropriate, construct a graph or graphs to present your data and show relationships between variables. Label the axes appropriately, include error bars if you know the error limits, and make sure that all of the data plotted in the graph are also available to the reader in tabular form. Hand-drawn graphs are preferable. If you use computer-generated graphs, make sure that they are labeled properly and tape or paste them into this section.

Conclusion

The following information should be entered after you complete the experiment:

• Results

  Write a one- or two-paragraph summary of the results of the experiment.

• Discussion

  Discuss, if possible quantitatively, the results you observed. Do your results confirm or refute the hypothesis? Record any thoughts you have that bear upon this experiment or possible related experiments you might perform to learn more. Suggest possible improvement to the experimental procedures or design.

• Answer questions

  If you’ve just completed a lab exercise from this or another book, answer all of the post-lab questions posed in the exercise. You can incorporate the questions by reference rather than writing them out again yourself.