Cliffs AP Chemistry, 3rd Edition

Laboratory Experiments

Approximately 5–10% of the AP Chemistry Exam is devoted to questions involving laboratory
experiments. Understanding basic laboratory concepts and being able to analyze sample data
will likely make the difference between a 4 and a 5 on the exam. The questions involving labo-
ratory experiments can be categorized into four main groups:

1. making observations of chemical reactions and substances


2. recording data


3. calculating and interpreting results based on the quantitative data obtained


4. communicating effectively the results of experimental work

Some colleges report that some students, while doing well on the written exam, have been at
serious disadvantage when they arrive at college because of inadequate or nonexistent labora-
tory experience in AP Chemistry at the high school. Completion of all recommended 22 labora-
tory experiments is essentialto doing the best possible on the AP Chemistry Exam. Meaningful
laboratory work is important in fulfilling the requirements of a college-level course of a labora-
tory science and in preparing you for sophomore-level chemistry courses in college. Issues of
college accreditation are also factors that must be considered, since colleges are giving you col-
lege laboratory credit for work that was supposedto be completed in the high school setting.
“Dry labs,” that is substituting real laboratory situations with worksheets or slide shows, are
unacceptable in preparing you for college-level work. Because chemistry professors at some
institutions will ask to see a record of the laboratory work that you did in AP Chemistry
before making a decision about granting credit, placement, or both, you must keep a neat,
well-organized laboratory notebook in such a fashion that the reports can be readily reviewed.
See page 233, on “The Laboratory Notebook” and page 256–282 for “A Sample Lab Report”.

“To play a violin, one needs to know how to handle it properly. To do a meaningful experi-

ment, one must mix and measure just as properly.”

Sienko, Plane and Marcus, 1984

Students involved in laboratory experiments in AP Chemistry should be familiar with basic lab-
oratory equipment, which will include but not be limited to:

• beakers, flasks, test tubes, crucibles, evaporating dishes, watch glasses, burners, plastic
  and glass tubing, stoppers, valves, spot plates, funnels, reagent bottles, wash bottles and
  droppers.

Students should also be familiar with measuring equipment, which will include, but not be
limited to:

• balances (to the nearest 0.001 g), thermometers, barometers, graduated cylinders, burets,
  volumetric pipets, graduated pipets, volumetric flasks, ammeters and voltmeters, pH me-
  ters, and spectrophotometers.