Chem 25 Chapter 11

Chem 25 Chapter 11
Study online at https://quizlet.com/_dike28
1. Electrons always flow in a voltaic (galvanic) cell from _____
A) the salt bridge to the anode
B) the oxidizing agent through the salt bridge to the reducing agent
C) the reducing agent through the salt bridge to the oxidizing agent
D) the anode to cathode
E) the salt bridge to the cathode: D) the anode to cathode
Explanation: Oxidation occurs at the anode and reduction at the cathode. This
means electrons are removed from the anode and flow toward the cathode.
2. A galvanic cell is represented by the shorthand Cu | Cu²z || Agz | Ag. Which
reaction occurs at the anode?
A) Cu(s) ’ Cu²z(aq) + 2e{
B) Agz(aq) + e{ ’ Ag(s)
C) Cu²z(aq) + 2e{ ’ Cu(s)
D) Ag(s) ’ Agz(aq) + :e{A) Cu(s) ’ Cu²z(aq) + 2e{
Explanation: A galvanic cell represented by the shorthand Cu | Cu²z || Agz | Ag, is
representation for the two half-reactions:
Cu(s) ’ Cu²z(aq) + 2e{, an oxidation occurring at the anode,
and
Agz(aq) + e{ ’ Ag(s), a reduction, occuring at the cathode.
3. A voltaic cell is prepared where copper metal is oxidized to copper(II) and
silver(I) is reduced to silver metal. Which of the following reactions occurs at
the anode?
A) 2 Cu(s) ’ 2 Cu²z(aq) + e{
B) Cu²z(aq) + 2e{ ’ Cu(s)
C) Cu(s) ’ Cu²z(aq) + 2e{
D) Agz(aq) + e{ ’ Ag(s)
E) Ag(s) ’ Agz(aq) + :e{C) Cu(s) ’ Cu²z(aq) + 2e{
Explanation: Oxidation, which is the loss of electrons, occurs at the anode. The
correctly balanced half-reaction for the oxidation of Cu isCu(s) ’ Cu²z(aq) + 2e{
4. Which of the following is the cell diagram for the reaction 3 Pb²z+(aq) + 2 Al(s
’ 3 Pb(s) + 2 Al³z(aq)?
A) Pb(s) | Pb²z(aq) || Al³z(aq) | Al(s)
B) Pb²z(aq) | Pb(s) || Al³z(aq) | Al(s)
C) Pb(s) | Pb²z(aq) || Al(s) | Al³z(aq)
D) Al(s) | Al³z(aq) || Pb²z(aq) | Pb(s)
E) Al³z(aq) | Al(s) || Pb(s) | Pb²z(aq)
: D) Al(s) | Al³z(aq) || Pb²z(aq) | Pb(s)
Explanation: 3 Pb²z+(aq) + 2 Al(s) ’ 3 Pb(s) + 2 Al³z(aq)
Al is being oxidized at the anode and Pb²z is being reduced at the cathode, so the

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, Chem 25 Chapter 11
Study online at https://quizlet.com/_dike28
cell diagram is
Al(s) | Al³z(aq) || Pb²z(aq) | Pb(s)
5. For the electrochemical cell represented by Cr²z | Cr³z || Liz | Li, E°(red) = -2
V. This cell:
A) Runs spontaneously
B) Does not run spontaneously
C) Is galvanic
D) Is electrolytic
E) Both (B) and (D): E) Both (B) and (D)
Explanation: An electrochemical cell with a negative voltage is not spontaneous, so it
occurs only if electrical energy is applied. Therefore both does not run spontaneously
and is electrolytic is correct.
6. If E°(red) of a given half-cell is more negative than E°(red) for a standard
hydrogen electrode, the half-cell will:
A) Tend to oxidize
B) Tend to reduce
C) Be at equilibrium
D) Not enough info: A) Tend to oxidize
Explanation: The half cell with the higher E°(red) in a galvanic cell will be reduced,
so if a half-cell has a more negative E°(red) than a standard hydrogen electrode, it
will tend to oxidize while hydrogen ion is reduced.
7. Which of the following species is the best reducing agent?
A) Pb
B) Agz
C) Mg
D) F{
E) Cu
*See table image on Chem 101: C) Mg
Explanation: The best reducing agent is the one most easily oxidized, which is the
one with the lowest reduction potential. From the choices on the list, Mg, with a
reduction potential of -2,36 V will be the best reducing agent.
8. In the redox reaction 6 Fe²z + Cr‚O‡²{ + 14 Hz ’ 2 Cr³z + 6 Fe³z + 7 H‚O, what
reducing agent?
A) Fe²z
B) Cr‚O‡²{
C) Hz
D) Cr³z
E) Fe³z : A) Fe²z
Explanation: Fe²z increases in oxidation number from +2 to +3 and the Cr in Cr‚O‡
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