Question 1

Which of the following best describes what occurs at the anode in a voltaic (galvanic) cell?

Accepted Answer

Oxidation occurs and electrons are lost by the electrode.

Question 2

Given the following redox reaction in acidic solution: $$\mathrm{Fe$$^{2+}$$ + $$MnO_4$$^- \rightarrow Fe$$^{3+}$$ + Mn$$^{2+}$$}$$, what is the correct balanced equation?

Accepted Answer

$$5\,\mathrm{Fe$$^{2+}$$} + \mathrm{$$MnO_4$$^-} + 8\,\mathrm{H^+} \rightarrow 5\,\mathrm{Fe$$^{3+}$$} + \mathrm{Mn$$^{2+}$$} + 4\,\mathrm{H_2O}$$

Question 3

Which of the following is the correct cell notation for a voltaic cell based on the reaction: $$\mathrm{Al(s) + Cr$$^{3+}$$(aq) \rightarrow Cr(s) + Al$$^{3+}$$(aq)}$$?

Accepted Answer

$$\mathrm{Al(s) | Al$$^{3+}$$(aq) || Cr$$^{3+}$$(aq) | Cr(s)}$$

Question 4

A copper strip is placed in a solution of silver nitrate. Which reaction occurs spontaneously?

Accepted Answer

$$\mathrm{Cu(s) + 2Ag^+(aq) \rightarrow Cu$$^{2+}$$(aq) + 2Ag(s)}$$

Question 5

Which of the following statements about the standard hydrogen electrode (SHE) is correct?

Accepted Answer

It is assigned a standard electrode potential of $$0.00\,\mathrm{V}.$$

Question 6

Calculate the standard cell potential, $$E^\circ_{cell}$$, for the reaction: $$\mathrm{Zn(s) + Cu$$^{2+}$$(aq) \rightarrow Zn$$^{2+}$$(aq) + Cu(s)}$$ given $$E^\circ_{red}(Cu$$^{2+}$$/Cu) = 0.34\,\mathrm{V}$$ and $$E^\circ_{red}(Zn$$^{2+}$$/Zn) = -0.76\,\mathrm{V}.$$

Accepted Answer

$$1.10\,\mathrm{V}$$

Question 7

Which of the following best explains why iron rusts more quickly in moist air than in dry air?

Accepted Answer

Water acts as an electrolyte, facilitating the redox reactions that lead to rust formation.

Question 8

Which equation correctly relates the standard cell potential to the equilibrium constant $$K at$$ $$25^\circ\mathrm{C}$$?

Accepted Answer

$$E^\circ_{cell} = \dfrac{0.0592\,\mathrm{V}}{n} \log K$$

Question 9

A voltaic cell is constructed with the following cell notation: $$\mathrm{Zn(s) | Zn$$^{2+}$$(1.0\,M) || Cu$$^{2+}$$(1.0\,M) | Cu(s)}. $$What will happen to the mass of the zinc and copper electrodes as the cell operates?

Accepted Answer

Zinc mass decreases, copper mass increases.

Question 10

Which of the following batteries is rechargeable and commonly used in hybrid vehicles due to its high energy density and environmental friendliness?

Accepted Answer

Nickel-metal hydride (Ni-MH) battery

Question 11

Which of the following is the correct Nernst equation for a cell at $$25^\circ\mathrm{C}$$?

Accepted Answer

$$E_{cell} = E^\circ_{cell} - \dfrac{0.0592\,\mathrm{V}}{n} \log Q$$

Question 12

During the electrolysis of molten NaCl, which species is produced at the cathode?

Accepted Answer

Sodium metal

Question 13

A current of $$2.00\,\mathrm{A} is $$passed through a solution of $$\mathrm{$$AgNO_3$$}$$ for $$1.50\,\mathrm{hours}. $$What mass of silver is deposited? ($$F = 96485\,\mathrm{C/mol}$$, $$M_{Ag} = 107.9\,\mathrm{g/mol})$$

Accepted Answer

$$12.1\,\mathrm{g}$$

Question 14

Which of the following statements is true regarding the relationship between $$\Delta G^\circ$$, $$E^\circ_{cell}$$, and $$K$$?

Accepted Answer

If $$E^\circ_{cell} \u003e 0$$, then $$\Delta G^\circ  1.$$

Question 15

Which of the following best describes cathodic protection of iron from corrosion?

Accepted Answer

Connecting iron to a more active metal, which acts as a sacrificial anode.

Question 16

In an electrolytic cell, which of the following is true?

Accepted Answer

The anode is positive and oxidation occurs there.

Question 17

Which of the following reactions is most likely to occur at the cathode during the electrolysis of an aqueous solution containing $$\mathrm{Na^+}$$, $$\mathrm{H_2O}$$, and $$\mathrm{Cl^-}$$ ions?

Accepted Answer

$$2\,\mathrm{H_2O} + 2e^- \rightarrow \mathrm{H_2$}(g) + 2\,\mathrm{OH^-}$$

Question 18

A concentration cell is constructed with two copper electrodes, one in $$0.010\,\mathrm{M}$$ $$\mathrm{Cu$$^{2+}$$}$$ and the other in $$2.0\,\mathrm{M}$$ $$\mathrm{Cu$$^{2+}$$}. $$Which direction do electrons flow?

Accepted Answer

From the electrode in $$0.010\,\mathrm{M}$$ $$\mathrm{Cu$$^{2+}$$} to $$the electrode in $$2.0\,\mathrm{M}$$ $$\mathrm{Cu$$^{2+}$$}$$

Electrochemistry: Redox Reactions, Electrochemical Cells, and Applications

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