Electrochem Pract 01

When the reaction quotient Q is more than Keq, _________ . (Choose the best two responses.) a. the reverse process is spontaneous but the forward process is not b. the forward and the reverse processes are both spontaneous c. the forward process is spontaneous but the reverse process is not d. the process is not spontaneous in either direction e. both forward and reverse processes have stopped f. ∆G > 0 g. ∆G < 0 h. ∆G = 0

a and f/the reverse process is spontaneous but the forward process is not and ∆G > 0

The more __________ the value of E°red, the greater the driving force for reduction. a. positive b. negative c. exothermic d. endothermic e. extensive

a/positive

In a voltaic cell electrons flow from the anode to the cathode. a. True b. False

a/true

When the cell potential is negative in a voltaic cell the cell reaction will not proceed spontaneously. a. True b. False

a/true

In a voltaic cell containing solid nickel, solid sodium, sodium sulfate, nickel(II) sulfate, and a sodium sulfate salt bridge, which of the following describes how the battery will work: (choose all that apply) a. solid sodium will be oxidized at the cathode and nickel(II) ions will be reduced at the anode b. solid sodium will be oxidized at the anode and nickel(II) ions will be reduced at the cathode c. electrons will flow across a wire towards the nickel(II) sulfate solution d. sodium additional cations will flow across the salt bridge towards the sodium sulfate solution e. solid nickel will be oxidized at the anode and sodium ions will be reduced at the cathode f. solid nickel will be oxidized at the cathode and sodium ions will be reduced at the anode

b and c/solid sodium will be oxidized at the anode and nickel(II) ions will be reduced at the cathode and electrons will flow across a wire towards the nickel(II) sulfate solution

In a voltaic cell containing solid tin, solid aluminum, aluminum sulfate, tin(II) sulfate, and a sodium sulfate salt bridge, which of the following describes how the battery will work: a. solid aluminum will be oxidized at the cathode and tin(II) ions will be reduced at the anode b. solid aluminum will be oxidized at the anode and tin(II) ions will be reduced at the cathode c. electrons will flow across the salt bridge towards the tin(II) sulfate solution d. sodium cations will flow across the salt bridge towards the tin(II) sulfate solution e. solid tin will be oxidized at the anode and aluminum ions will be reduced at the cathode f. solid tin will be oxidized at the cathode and aluminum ions will be reduced at the anode

b and d/solid aluminum will be oxidized at the anode and tin(II) ions will be reduced at the cathode and sodium cations will flow across the salt bridge towards the tin(II) sulfate solution

Which of the following substances will successfully oxidize tin (Sn) metal under standard thermodynamic conditions? (select all that apply) (Note language/verb variation: substance A oxidizes substance B means the same thing as both substance A is reduced and substance B is oxidized.) a. Mg2+ b. H+ c. Li+ d. Na+ e. Pb2+ f. Al3+ g. Cu(s) h. Ni(s)

b and e/H+ and PB2+

The electrode where reduction occurs is called the anode. a. True b. False

b/false

The balanced half-reaction in which chlorine gas is reduced to the aqueous chloride ion is a __________ process. a. one-electron b. two-electron c. four-electron d. three-electron e. six-electron

b/two-electron

Which of the following substances will successfully oxidize copper metal under standard thermodynamic conditions? (select all that apply) (Note language/verb variation: substance A oxidizes substance B means the same thing as both substance A is reduced and substance B is oxidized.) a. Zn2+ b. H+ c. Ag+ d. Cl2 e. Pb2+ f. Al3+ g. Au(s) h. Cu(s) i. Fe3+

c and d/Ag+ and Cl2 OR c and i/Ag+ and Fe3+

When the reaction quotient Q is less than Keq, _________ . (Choose the best two responses.) a. the reverse process is spontaneous but the forward process is not b. the forward and the reverse processes are both spontaneous c. the forward process is spontaneous but the reverse process is not d. the process is not spontaneous in either direction e. both forward and reverse processes have stopped f. ∆G > 0 g. ∆G < 0 h. ∆G = 0

c and g/the forward process is spontaneous but the reverse process is not and ∆G < 0

Which of the halogens in Table 20.1 is the strongest oxidizing agent (steals electrons the best)? a. Cl2 b. Br2 c. F2 d. I2 e. All of the halogens have equal strength as oxidizing agents.

c/F2

Which one of the following is the best oxidizing agent? a. H2 b. Na c. O2 d. Li e. Ca

c/O2

When a system is at equilibrium, __________. (Choose the best two responses.) a. the reverse process is spontaneous but the forward process is not b. the forward and the reverse processes are both spontaneous c. the forward process is spontaneous but the reverse process is not d. the process is not spontaneous in either direction e. both forward and reverse processes have stopped f. ∆G > 0 g. ∆G < 0 h. ∆G = 0

d and h/the process is not spontaneous in either direction and ∆G = 0

What is the oxidation number of bromine in the BrO3- ion? a. -1 b. +1 c. +3 d. +5 e. +7

d/+5

What is the oxidation number of nitrogen in the HNO3? a. -1 b. +1 c. +3 d. +5 e. +7

d/+5

What is the oxidation number of chromium in Cr2O ion? a. +3 b. +12 c. +7 d. +6 e. +14

d/+6

The electrode at which oxidation occurs is called the __________. a. oxidizing agent b. cathode c. reducing agent d. anode e. voltaic cell

d/anode

Which of the following substances will successfully oxidize silver metal under standard thermodynamic conditions? (select all that apply) (Note language/verb variation: substance A oxidizes substance B means the same thing as both substance A is reduced and substance B is oxidized.) a. Mg2+ b. H+ c. Fe3+ d. H2 e. Hg2+ f. Co3+ g. I2 h. Cu(s)

e and f/Hg2+ and Co3+

Which one of the following types of elements is most likely to be a good oxidizing agent? a. alkali metals b. lanthanides c. alkaline earth elements d. transition elements e. halogens

e/halogens

The relationship between the change in Gibbs free energy and the emf of an electrochemical cell is given by __________.

∆G=-nFE