Question 1

Which statement best describes the role of the anode in a galvanic (voltaic) cell?

Accepted Answer

The anode is where oxidation occurs and electrons are lost.

Question 2

Given the reaction $$\mathrm{Zn(s) + 2H^+(aq) \rightarrow Zn$$^{2+}$$(aq) + H_2$(g)}$$, what is the change in oxidation number for zinc?

Accepted Answer

From 0 to +2, indicating oxidation.

Question 3

In the reaction $$\mathrm{$$MnO_4$$^- + C_2O_4$$^{2-}$$ \rightarrow Mn$$^{2+}$$ + CO_2$}$$, which species is oxidized and which is reduced?

Accepted Answer

MnO$$_4^- is $$reduced, C$$_2O$_4$$^{2-}$$ is oxidized.

Question 4

What is the correct order for balancing a redox equation using the half-reaction method?

Accepted Answer

Balance other atoms, balance O by adding H$$_2O$$, balance H by adding H$$^+$$, balance electrons.

Question 5

In a Daniell cell, which direction do electrons flow?

Accepted Answer

From the zinc electrode to the copper electrode.

Question 6

Which equation correctly relates the standard cell potential ($$E^\circ_{cell}) to $$the standard reduction potentials of the cathode and anode?

Accepted Answer

$$E^\circ_{cell} = E^\circ_{red}(cathode) - E^\circ_{red}(anode)$$

Question 7

If the standard reduction potential for $$\mathrm{Zn$$^{2+}$$/Zn} is$$ $$-0.76 V $$and for $$\mathrm{Cu$$^{2+}$$/Cu} is$$ $$+0.34 V$$, what is the standard cell potential for a cell with zinc as the anode and copper as the cathode?

Accepted Answer

$$+1.10 V$$

Question 8

Which of the following statements about the salt bridge in a galvanic cell is correct?

Accepted Answer

It maintains electrical neutrality by allowing ions to migrate.

Question 9

What is the relationship between standard free energy change ($$\Delta G^\circ) $$and standard cell potential ($$E^\circ$$)?

Accepted Answer

$$\Delta G^\circ = -nFE^\circ$$

Question 10

A battery is constructed with a nickel anode and a nickel cathode in a nickel plating process. What is the cell potential under standard conditions?

Accepted Answer

$$0 V$$

Question 11

Which species would be the best oxidizing agent based on the following reduction potentials: $$E^\circ_{red}(F_2$/F^-) = +2.87 V$, E$$^\circ_{red}($$MnO_4$$^$$-/Mn^{2+}) = +1.51$ V$$, $$E^\circ_{red}(Cl_2$/Cl^-) = +1.36 V$?

Accepted Answer

F$$_2$$

Question 12

Which equation represents the Nernst equation for a cell under non-standard conditions?

Accepted Answer

$$E = E^\circ - \frac{RT}{nF} \ln Q$$

Question 13

In an electrolytic cell used for electroplating, which statement is true?

Accepted Answer

Reduction occurs at the cathode.

Question 14

How many grams of silver can be deposited from Ag$$^+$$ solution by passing 193,000 C of charge? (Molar mass of Ag = 107.87 g/mol, $$F = 96,485 C/$$mol)

Accepted Answer

Question 15

Which of the following best explains why the cell potential does not change when the reaction is halved (e.g., $$2Ag(s) + \frac{1}{2}O_2$(g) + 2H^+(aq) \rightarrow 2Ag^+(aq) + H_2O(l)$$)?

Accepted Answer

Cell potential is an intensive property and does not scale with the amount of reaction.

Question 16

Which of the following is true for a spontaneous redox reaction in a galvanic cell?

Accepted Answer

$$E^\circ_{cell} \u003e 0$$

Question 17

In a concentration cell, what causes the measured potential?

Accepted Answer

The difference in ion concentrations between the two half-cells.

Question 18

Which equation correctly relates the equilibrium constant ($$K) to $$the standard cell potential ($$E^\circ$$)?

Accepted Answer

$$E^\circ = \frac{RT}{nF} \ln K$$

Question 19

Which of the following statements about Faraday’s Law of Electrolysis is correct?

Accepted Answer

The amount of substance created is directly proportional to the electrical charge passed.

Electrochemistry: Principles, Cells, and Applications

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