Name: Date:
Part A: Knowledge and Understanding ( /10 )
1. The electrode at which oxidation occurs is called the
a. oxidizing agent
b. cathode
c. reducing agent
d. anode
2. Which of the following is an oxidation-reduction reaction?
a. Na → Na+ + 1e-
b. 2 SO2 + O2 → 2 SO3
c. N2O4 → 2 NO2
d. 2 e- + F2 → 2 F-
3. Which element is oxidized in the chemical reaction shown by the following chemical
equation?
3 Cu (s) + 8HNO3 (aq) → 3 Cu(NO3)2 (aq) + 2 NO (g) + 4 H2O (l)
a. Cu
b. H
c. N
d. O
e. This is not a redox reaction
4. In the reaction Fe → Fe3+ + 3e-, the species Fe is
a. oxidized
b. reduced
c. electrolyzed
d. the oxidizing agent
5. In which of the following molecules does hydrogen have an oxidation state of -1?
a. H2O
b. NH3
c. CaH2
d. CH4
e. H2
6. What are the oxidation numbers in the compound H3PO4?
a. H = +1 , P = 0 , O = -2
b. H = +1 , P = +5 , O = -2
c. H = -1 , P = +7 , O = -1
d. H = +1 , P = + 1, O = -1
, Al3+ + 3e- → Al(s) Eo = -1.66 V
Cr3+ + 3e- → Cr(s) Eo = -0.73 V
7. The standard reduction potentials for two half-reactions are shown above. Which of the
statements listed below will be true for the following reaction taking place under standard
conditions?
Al (s) + Cr3+ → Al3+ + Cr (s)
a. Eo = 2.39 V, and the reaction is not spontaneous
b. Eo = 0.93 V, and the reaction is spontaneous
c. Eo = - 0.93 V, and the reaction is not spontaneous
d. Eo = - 0.93 V, and the reaction is spontaneous
e. Eo = - 2.39 V, and the reaction is not spontaneous
Cu2+ + 2e- → Cu Eo = +0.34 V
Zn2+ + 2e- → Zn Eo = -0.76 V
Mn2+ + 2e- → Mn Eo = -1.18 V
8. Based on the above reduction potential, which of the following reactions will occur
spontaneously?
a. Mn2+ + Cu → Mn + Cu2+
b. Mn2+ + Zn → Mn + Zn2+
c. Zn2+ + Cu → Zn + Cu2+
d. Zn2+ + Mn → Zn + Mn2+
e. Cu2+ + Zn2+ → Cu + Zn
9. The redox reaction 4H+ + N2 → NH 4+ + N is
a. correctly balanced
b. correctly balanced for number of atoms but not for charge
c. correctly balanced for charge but not for number of atoms
d. not balanced for number of atoms or for charge
10. The purpose of the salt bridge in an electrochemical cell is to
a. maintain electrical neutrality in the half cells via migration of ions.
b. provide a source of ions to react at the anode and cathode.
c. provide a means for electrons to travel from anode to cathode.
d. provide a means for electrons to travel from the cathode to the anode.
Part A: Knowledge and Understanding ( /10 )
1. The electrode at which oxidation occurs is called the
a. oxidizing agent
b. cathode
c. reducing agent
d. anode
2. Which of the following is an oxidation-reduction reaction?
a. Na → Na+ + 1e-
b. 2 SO2 + O2 → 2 SO3
c. N2O4 → 2 NO2
d. 2 e- + F2 → 2 F-
3. Which element is oxidized in the chemical reaction shown by the following chemical
equation?
3 Cu (s) + 8HNO3 (aq) → 3 Cu(NO3)2 (aq) + 2 NO (g) + 4 H2O (l)
a. Cu
b. H
c. N
d. O
e. This is not a redox reaction
4. In the reaction Fe → Fe3+ + 3e-, the species Fe is
a. oxidized
b. reduced
c. electrolyzed
d. the oxidizing agent
5. In which of the following molecules does hydrogen have an oxidation state of -1?
a. H2O
b. NH3
c. CaH2
d. CH4
e. H2
6. What are the oxidation numbers in the compound H3PO4?
a. H = +1 , P = 0 , O = -2
b. H = +1 , P = +5 , O = -2
c. H = -1 , P = +7 , O = -1
d. H = +1 , P = + 1, O = -1
, Al3+ + 3e- → Al(s) Eo = -1.66 V
Cr3+ + 3e- → Cr(s) Eo = -0.73 V
7. The standard reduction potentials for two half-reactions are shown above. Which of the
statements listed below will be true for the following reaction taking place under standard
conditions?
Al (s) + Cr3+ → Al3+ + Cr (s)
a. Eo = 2.39 V, and the reaction is not spontaneous
b. Eo = 0.93 V, and the reaction is spontaneous
c. Eo = - 0.93 V, and the reaction is not spontaneous
d. Eo = - 0.93 V, and the reaction is spontaneous
e. Eo = - 2.39 V, and the reaction is not spontaneous
Cu2+ + 2e- → Cu Eo = +0.34 V
Zn2+ + 2e- → Zn Eo = -0.76 V
Mn2+ + 2e- → Mn Eo = -1.18 V
8. Based on the above reduction potential, which of the following reactions will occur
spontaneously?
a. Mn2+ + Cu → Mn + Cu2+
b. Mn2+ + Zn → Mn + Zn2+
c. Zn2+ + Cu → Zn + Cu2+
d. Zn2+ + Mn → Zn + Mn2+
e. Cu2+ + Zn2+ → Cu + Zn
9. The redox reaction 4H+ + N2 → NH 4+ + N is
a. correctly balanced
b. correctly balanced for number of atoms but not for charge
c. correctly balanced for charge but not for number of atoms
d. not balanced for number of atoms or for charge
10. The purpose of the salt bridge in an electrochemical cell is to
a. maintain electrical neutrality in the half cells via migration of ions.
b. provide a source of ions to react at the anode and cathode.
c. provide a means for electrons to travel from anode to cathode.
d. provide a means for electrons to travel from the cathode to the anode.
