Question 1

Which of the following statements best describes the process of oxidation in an electrochemical reaction?

Accepted Answer

A species loses electrons and its oxidation number increases.

Question 2

In the reaction $$\mathrm{Zn(s) + 2H^+(aq) \rightarrow Zn$$^{2+}$$(aq) + H_2$(g)}$$, what is the oxidizing agent?

Accepted Answer

H$$^+(aq)$$

Question 3

Assign the oxidation number to chlorine in $$\mathrm{$$ClO_3$$^-}.$$

Accepted Answer

$$+5$$

Question 4

Which of the following is true for a galvanic (voltaic) cell?

Accepted Answer

The anode is negative and the cathode is positive.

Question 5

What is the standard cell potential ($$E_{cell}^\circ) $$for a cell with the following half-reactions?

$$\mathrm{Cu$$^{2+}$$ + 2e^- \rightarrow Cu(s)}$$ $$E_{red}^\circ = +0.34\,V$$ 
$$\mathrm{Zn$$^{2+}$$ + 2e^- \rightarrow Zn(s)}$$ $$E_{red}^\circ = -0.76\,V$$

Accepted Answer

$$+1.10\,V$$

Question 6

Which of the following best describes the function of a salt bridge in a voltaic cell?

Accepted Answer

It maintains electrical neutrality by allowing ions to migrate between half-cells.

Question 7

Given the reaction $$\mathrm{$$MnO_4$$^- + 5Fe$$^{2+}$$ + 8H^+ \rightarrow Mn$$^{2+}$$ + 5Fe$$^{3+}$$ + 4H_2O}$$, how many electrons are transferred in the balanced equation?

Accepted Answer

5

Question 8

Which of the following is the correct Nernst equation for a cell at 25°C ($$298\,K$$)?

Accepted Answer

$$E = E^\circ - \dfrac{0.0592}{n} \log Q$$

Question 9

A battery is constructed using the following half-reactions: 
$$\mathrm{Ag^+ + e^- \rightarrow Ag(s)}$$ $$E_{red}^\circ = +0.80\,V$$ 
$$\mathrm{Cu$$^{2+}$$ + 2e^- \rightarrow Cu(s)}$$ $$E_{red}^\circ = +0.34\,V$$ 
Which metal will be deposited at the cathode?

Accepted Answer

Silver

Question 10

Which of the following statements about electrolytic cells is correct?

Accepted Answer

The anode is positive and oxidation occurs there.

Question 11

Calculate the mass of aluminum produced in 1.0 hour by the electrolysis of molten $$\mathrm{$$AlCl_3$$} if $$the current is $$20\,A$$. ($$\mathrm{Al$$^{3+}$$ + 3e^- \rightarrow Al}$$, $$M_{Al} = 27.0\,g/mol$$, $$F = 96,500\,C/mol)$$

Accepted Answer

$$6.7\,g$$

Question 12

Which of the following best describes the relationship between cell potential and spontaneity for a redox reaction?

Accepted Answer

A positive cell potential ($$E_{cell}) $$indicates a spontaneous reaction.

Question 13

Which of the following is the correct expression for the standard free energy change ($$\Delta G^\circ) $$for a redox reaction?

Accepted Answer

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

Question 14

In the electrolysis of aqueous $$\mathrm{NaCl}$$, which product is formed at the cathode?

Accepted Answer

$$\mathrm{H_2$(g)}$$

Question 15

Which of the following is a correct cell notation for a voltaic cell involving the reaction $$\mathrm{Zn(s) + Cu$$^{2+}$$(aq) \rightarrow Zn$$^{2+}$$(aq) + Cu(s)}$$?

Accepted Answer

$$\mathrm{Zn(s) | Zn$$^{2+}$$(aq) || Cu$$^{2+}$$(aq) | Cu(s)}$$

Question 16

If the cell potential ($$E_{cell}) $$for a reaction is zero, what does this indicate about the reaction?

Accepted Answer

The reaction is at equilibrium.

Question 17

Which of the following best describes the role of the Faraday constant ($$F) in $$electrochemistry?

Accepted Answer

It is the charge of one mole of electrons.

Question 18

Which of the following is the correct balanced half-reaction for the reduction of permanganate ion ($$\mathrm{$$MnO_4$$^-}) to$$ $$\mathrm{Mn$$^{2+}$$} in $$acidic solution?

Accepted Answer

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

Question 19

Which of the following best explains why corrosion (rusting) is considered an electrochemical process?

Accepted Answer

It involves the transfer of electrons from iron to oxygen.

Electrochemistry: Principles, Calculations, and Applications

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