Question 1

Which of the following statements best describes the difference between a voltaic (galvanic) cell and an electrolytic cell?

Accepted Answer

A voltaic cell produces electricity from a spontaneous redox reaction, while an electrolytic cell uses electricity to drive a non-spontaneous reaction.

Question 2

In the standard hydrogen electrode (SHE), which of the following is true?

Accepted Answer

The SHE has a standard electrode potential of $$0.00\ \mathrm{V}.$$

Question 3

Given the following cell notation: $$\mathrm{Zn}(s)\ |\ \mathrm{Zn}^{2+}(aq)\ ||\ \mathrm{H}^{+}(aq)\ |\ \mathrm{H}_2(g)\ |\ \mathrm{Pt}(s)$$, which electrode is the anode?

Accepted Answer

Zn(s)

Question 4

Which equation correctly represents the Nernst equation at $$25^\circ\mathrm{C}$$ for a cell reaction involving $$n$$ electrons?

Accepted Answer

$$E_{\mathrm{cell}} = E_{\mathrm{cell}}^\circ - \dfrac{0.0592}{n} \log Q$$

Question 5

A concentration cell is constructed as follows: $$\mathrm{Cu}(s)\ |\ \mathrm{Cu}^{2+}(0.05\ \mathrm{M})\ ||\ \mathrm{Cu}^{2+}(0.50\ \mathrm{M})\ |\ \mathrm{Cu}(s). $$What is the cell potential at $$25^\circ\mathrm{C}$$?

Accepted Answer

$$0.030\ \mathrm{V}$$

Question 6

Which of the following best explains why a hydrogen fuel cell is considered environmentally friendly?

Accepted Answer

It produces only water as a byproduct when generating electricity.

Question 7

During the electrolysis of water, which half-reaction occurs at the cathode?

Accepted Answer

$$2\mathrm{H}_2\mathrm{O}(l) + 2e^- \rightarrow \mathrm{H}_2(g) + 2\mathrm{OH}^-(aq)$$

Question 8

If a current of $$100\ \mathrm{A} is $$applied for $$5$$ minutes during the electrolysis of water, how many moles of $$\mathrm{H}_2(g)$$ will be produced? (Faraday's constant $$= 96485\ \mathrm{C/mol\ e^-})$$

Accepted Answer

$$0.155$$ moles

Question 9

Which of the following is the correct application of Faraday's law of electrolysis?

Accepted Answer

The amount of substance produced at an electrode is directly proportional to the quantity of charge passed through the cell.

Question 10

A voltaic cell is constructed using the following half-cells: $$\mathrm{Sn}^{2+}/\mathrm{Sn}$$ and $$\mathrm{Cu}^{2+}/\mathrm{Cu}. If $$the standard reduction potentials are $$E^\circ(\mathrm{Sn}^{2+}/\mathrm{Sn}) = -0.14\ \mathrm{V}$$ and $$E^\circ(\mathrm{Cu}^{2+}/\mathrm{Cu}) = +0.34\ \mathrm{V}$$, what is the standard cell potential?

Accepted Answer

$$+0.48\ \mathrm{V}$$

Question 11

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

Accepted Answer

It maintains electrical neutrality by allowing the flow of ions between the half-cells.

Question 12

In a lithium-ion battery, which process occurs at the anode during discharge?

Accepted Answer

Oxidation of lithium atoms, releasing electrons.

Question 13

Which of the following correctly describes the relationship between $$\Delta G$$ and $$E_{\mathrm{cell}}$$ for an electrochemical cell?

Accepted Answer

$$\Delta G = -nFE_{\mathrm{cell}}$$

Question 14

A neuron membrane potential is calculated using the Nernst equation. If the concentration of $$\mathrm{K}^+$$ inside the cell is $$140\ \mathrm{mM}$$ and outside is $$4\ \mathrm{mM}$$, what is the sign of the membrane potential ($$E_{\mathrm{cell}}) $$for $$\mathrm{K}^+$$?

Accepted Answer

Negative

Question 15

How many coulombs of charge are required to produce $$1.00$$ mole of $$\mathrm{O}_2$$ gas from water by electrolysis? (Assume the reaction: $$2\mathrm{H}_2\mathrm{O}(l) \rightarrow \mathrm{O}_2(g) + 4\mathrm{H}^+(aq) + 4e^-)$$

Accepted Answer

$$4 	imes 96485\ \mathrm{C}$$

Question 16

Which of the following statements about electrolysis is correct?

Accepted Answer

Electrolysis requires an input of electrical energy to drive a non-spontaneous reaction.

Question 17

If a current of $$500\ \mathrm{A} is $$used to produce $$1$$ mole of $$\mathrm{O}_2 by $$electrolysis of water, how long (in minutes) will it take? (Faraday's constant $$= 96485\ \mathrm{C/mol\ e^-})$$

Accepted Answer

$$12.9$$ min

Question 18

Which of the following is a correct cell notation for a concentration cell using silver electrodes and $$\mathrm{Ag}^+$$ solutions of $$0.10\ \mathrm{M}$$ and $$1.0\ \mathrm{M}$$?

Accepted Answer

$$\mathrm{Ag}(s)\ |\ \mathrm{Ag}^+(0.10\ \mathrm{M})\ ||\ \mathrm{Ag}^+(1.0\ \mathrm{M})\ |\ \mathrm{Ag}(s)$$

Question 19

Which of the following best describes what happens at the anode in a voltaic cell?

Accepted Answer

Oxidation occurs and electrons are released.

Electrochemistry: Galvanic and Electrolytic Cells, Concentration Cells, Fuel Cells, and Electrolysis

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