Electrochemistry ❮ 253❯ Review Questions
Use these questions to review the content of this chapter and practice for the AP Chemistry
exam. First are 18 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.Choose one of the following for questions 1 and 2.
(A) There is no change in the voltage.
(B) The voltage becomes zero.
(C) The voltage increases.
(D) The voltage decreases but stays positive.The following reaction takes place in a voltaic cell:
Zn(s) + Cu^1 +(1 M) → Cu(s) + Zn^2 +(1 M)
The cell has a voltage that is measured and found to
be +1.10 V.
- What happens to the cell voltage when the
copper electrode is made smaller? - What happens to the cell voltage when the salt
bridge is filled with deionized water instead of
1 M KNO 3? - MnO 4 - (aq) + H+(aq) + C 2 O 42 - (aq) → Mn^2 +(aq)
- H+ + CO 2 (g)
What is the coefficient of H+ when the above
reaction is balanced?
(A) 16
(B) 2
(C) 8
(D) 5
- S 2 O 32 - (aq) + OH-(aq) → SO 42 - (aq) + H 2 O(l) + e-
After the above half-reaction is balanced, which
of the following are the respective coefficients of
OH- and SO 42 -?
(A) 8 and 3
(B) 6 and 2
(C) 10 and 2
(D) 5 and 2
- How many moles of Pt may be deposited on
the cathode when 0.80 F of electricity is passed
through a 1.0 M solution of Pt^4 +?
(A) 1.0 mole
(B) 0.60 mole
(C) 0.20 mole
(D) 0.80 mole - A chemistry student obtains the following answer
when balancing a redox equation:
Cr 2 O 72 - (aq) + 14 H+(aq) + 3 S^2 - (aq) →
2 Cr^3 +(aq) + 3 S(s) + 7 H 2 O(l)
Which of the following is the true statement con-
cerning the balanced equation?
(A) The Cr 2 O 72 - reduces the S^2 -.
(B) The oxidation number of chromium changes
from +7 to +3.
(C) The oxidation number of sulfur remains –2.
(D) The Cr 2 O 72 - oxidizes the S^2 -. - H+(aq) + NO 3 - (aq) + e- → NO(g) + H 2 O(g)
What is the coefficient for water when the above
half-reaction is balanced?
(A) 3
(B) 4
(C) 2
(D) 1