204 ❯ STEP 4. Review the Knowledge You Need to Score High
❯ Review Questions
Use these questions to review the content of this chapter and practice for the AP Chemistry
exam. First are 16 multiple-choice questions similar to what you will encounter in Section I
of the AP Chemistry exam. Following those is a long free-response question like the ones
in Section II of the exam. To make these questions an even more authentic practice for the
actual exam, time yourself following the instructions provided.Multiple-Choice Questions
Answer the following questions in 25 minutes. You may not use a calculator. You may use
the periodic table and the equation sheet at the back of this book.- A reaction follows the rate law Rate = k[A]^2.
Which of the following plots will give a straight
line?
(A) 1/[A] versus 1/time
(B) [A]^2 versus time
(C) 1/[A] versus time
(D) ln[A] versus time - For the reaction NO 2 (g) + CO(g) → NO(g) +
CO 2 (g), the rate law is Rate = k[NO 2 ]^2. If a small
amount of gaseous carbon monoxide (CO) is
added to a reaction mixture that was 0.10 molar
in NO 2 and 0.20 molar in CO, which of the fol-
lowing statements is true?
(A) Both k and the reaction rate remain the same.
(B) Both k and the reaction rate increase.
(C) Both k and the reaction rate decrease.
(D) Only k increases; the reaction rate will remain
the same. - The radioactive decay of tritium,^3 H, has a half-
life of 12.3 years. Radioactive decay processes
follow first-order kinetics. How long will it for
the moles of tritium in a sample to decrease from
1.00 mole to 0.0625 mole?
(A) 12.3 y
(B) 24.6 y
(C) 49.2 y
(D) 98.4 y
4. The rate of reaction for a certain chemical is slow.
A possible cause of the slow rate might be which
of the following?
(A) The activation energy is low.
(B) The activation energy is high.
(C) There is a catalyst present.
(D) There was an increase in the temperature.
5. The steps below represent a proposed mechanism
for the catalyzed oxidation of CO by O 3.
Step 1: NO 2 (g) + CO(g) → NO(g) + CO 2 (g)
Step 2: NO(g) + O 3 (g) → NO 2 (g) + O 2 (g)
What are the overall products of the catalyzed
reaction?
(A) CO 2 and O 2
(B) NO and CO 2
(C) NO 2 and O 2
(D) NO and O 2 - The decomposition of ammonia to the elements
is a first-order reaction with a half-life of 200 s
at a certain temperature. How long will it take
the partial pressure of ammonia to decrease from
0.100 atm to 0.00625 atm?
(A) 200 s
(B) 400 s
(C) 800 s
(D) 1,000 s