Q: Which of the following half-reactions has the highest tendency to be reduced under standard conditions at 25 $$^\\circC$$?

$$\\text{Ag}^+ + e^- \\rightarrow \\text{Ag}$$

Q: Which of the following reactions is spontaneous under standard conditions at 25 $$^\\circC$$?

$$\\text{Zn} + 2\\text{H}^+ \\rightarrow \\text{Zn}^{2+} + \\text{H}_2$$

Q: A student claims that $$\\text{Fe}^{2+}$$ can reduce $$\\text{Ag}^+ to$$ $$\\text{Ag}$$ under standard conditions. Is this correct?

No, because $$E^\\circ(\\text{Fe}^{3+}/\\text{Fe}^{2+}) is $$lower than $$E^\\circ(\\text{Ag}^+/\\text{Ag}).$$

Q: Which of the following is the correct cell notation for a galvanic cell with $$\\text{Zn} as $$the anode and $$\\text{Cu} as $$the cathode?

$$\\text{Zn} | \\text{Zn}^{2+} || \\text{Cu}^{2+} | \\text{Cu}$$

Q: Which of the following pairs can be used to construct a galvanic cell with the largest possible standard cell potential?

$$\\text{Li}^+/\\text{Li}$$ \\text{ and } \\text{F}_2/\\text{F}^-$

Question 1

Which of the following half-reactions has the highest tendency to be reduced under standard conditions at 25 $$^\circC$$?

Accepted Answer

$$\text{Ag}^+ + e^- \rightarrow \text{Ag}$$

Question 2

A galvanic cell is constructed using the following half-cells: $$\text{Zn}^{2+}/\text{Zn}$$ and $$\text{Cu}^{2+}/\text{Cu}. $$Which metal acts as the anode?

Accepted Answer

Zinc

Question 3

Given the standard reduction potentials: $$E^\circ(\text{Ag}^+ / \text{Ag}) = +0.80 V $$and $$E^\circ(\text{Cu}^{2+} / \text{Cu}) = +0.34 V$$, which species is the stronger oxidizing agent?

Accepted Answer

$$\text{Ag}^+$$

Question 4

Which of the following reactions is spontaneous under standard conditions at 25 $$^\circC$$?

Accepted Answer

$$\text{Zn} + 2\text{H}^+ \rightarrow \text{Zn}^{2+} + \text{H}_2$$

Question 5

If $$E^\circ_{cell} is $$positive for a redox reaction, what does this indicate about the reaction under standard conditions?

Accepted Answer

The reaction is spontaneous.

Question 6

Which of the following metals can reduce $$\text{Cu}^{2+} to$$ $$\text{Cu}$$ under standard conditions?

Accepted Answer

$$\text{Zn}$$

Question 7

A student claims that $$\text{Fe}^{2+}$$ can reduce $$\text{Ag}^+ to$$ $$\text{Ag}$$ under standard conditions. Is this correct?

Accepted Answer

No, because $$E^\circ(\text{Fe}^{3+}/\text{Fe}^{2+}) is $$lower than $$E^\circ(\text{Ag}^+/\text{Ag}).$$

Question 8

Calculate the standard cell potential for the reaction: $$\text{Zn} + 2\text{Ag}^+ \rightarrow \text{Zn}^{2+} + 2\text{Ag}. $$Use $$E^\circ(\text{Ag}^+/\text{Ag}) = +0.80 V $$and $$E^\circ(\text{Zn}^{2+}/\text{Zn}) = -0.76 V.$$

Accepted Answer

$$E^\circ_{cell} = +1.56 V$$

Question 9

Which of the following statements best explains why gold ($$\text{Au}) $$does not corrode easily?

Accepted Answer

Gold has a very positive standard reduction potential.

Question 10

In a medical device, a galvanic cell uses $$\text{Mg}$$ and $$\text{Cu}$$ electrodes. Which metal will dissolve (lose mass) as the cell operates?

Accepted Answer

$$\text{Mg}$$

Question 11

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

Accepted Answer

It maintains electrical neutrality by allowing ion flow.

Question 12

A silver spoon is placed in a solution of $$\text{Cu}^{2+}. $$What will happen under standard conditions?

Accepted Answer

No reaction will occur.

Question 13

Which of the following is the correct cell notation for a galvanic cell with $$\text{Zn} as $$the anode and $$\text{Cu} as $$the cathode?

Accepted Answer

$$\text{Zn} | \text{Zn}^{2+} || \text{Cu}^{2+} | \text{Cu}$$

Question 14

Which of the following metals is most easily oxidized under standard conditions?

Accepted Answer

$$\text{Zn}$$

Question 15

A battery uses the reaction $$2\text{Fe}^{3+} + 2\text{I}^- \rightarrow 2\text{Fe}^{2+} + \text{I}_2. $$Which species is oxidized?

Accepted Answer

$$\text{I}^-$$

Question 16

Which of the following best explains why $$\text{H}_2$$ gas can be used as a reference electrode in electrochemistry?

Accepted Answer

It has a standard reduction potential defined as zero.

Question 17

If $$E^\circ_{cell}$$ for a reaction is $$-0.40 V$$, what can you conclude about the spontaneity of the reaction under standard conditions?

Accepted Answer

The reaction is nonspontaneous.

Question 18

Which of the following pairs can be used to construct a galvanic cell with the largest possible standard cell potential?

Accepted Answer

$$\text{Li}^+/\text{Li}$$ \text{ and } \text{F}_2/\text{F}^-$

Question 19

A jewelry cleaner uses an electrolytic cell to plate silver onto a spoon. Which electrode is the spoon attached to?

Accepted Answer

Cathode

Standard Electrode Potentials and Redox Activity

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