Q: Given the following half-reactions and their standard reduction potentials: $$\text{Ni}^{2+}(aq) + 2e^- \rightarrow \text{Ni}(s)$$ $$E^ ext{o} = -0.23\,\text{V}$$ $$\text{Al}^{3+}(aq) + 3e^- \rightarrow \text{Al}(s)$$ $$E^ ext{o} = -1.66\,\text{V}$$ What is the standard cell potential ($$E^ ext{o}_\text{cell}) $$for the reaction: $$3\text{Ni}^{2+}(aq) + 2\text{Al}(s) \rightarrow 3\text{Ni}(s) + 2\text{Al}^{3+}(aq)$$?

$$E^ ext{o}_\text{cell} = +1.43\,\text{V}$$

Q: Using the Nernst equation, calculate the cell potential for the following reaction at $$25^\circC $$when $$[\text{Cu}^{2+}] = 2.0\,\text{M}$$ and $$[\text{Zn}^{2+}] = 0.010\,\text{M}$$: $$\text{Cu}^{2+}(aq) + \text{Zn}(s) \rightarrow \text{Cu}(s) + \text{Zn}^{2+}(aq)$$ Given $$E^ ext{o}_\text{cell} = 1.10\,\text{V}.$$

$$E_\text{cell} = 1.10 + 0.0592 \log \left( \frac{0.010}{2.0} \right)$$

Q: Which equation correctly relates the standard free energy change to the standard cell potential?

$$\Delta G^\text{o} = -nFE^\text{o}_\text{cell}$$

Q: Which of the following is true for a cell where $$Q = 0.0010$$ and $$K = 0.10$$?

$$E_\text{cell} is $$positive and $$E^\text{o}_\text{cell} is $$negative

Q: Which equation is used to calculate the equilibrium constant $$K$$ from the standard cell potential $$E^\text{o}_\text{cell}$$?

$$E^\text{o}_\text{cell} = \frac{0.0592}{n} \log K$$

Q: For the reaction $$\text{Zn}(s) + 2\text{H}^+(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{H}_2(g)$$, what is the standard cell potential if the standard hydrogen electrode (SHE) is used as the cathode?

$$E^\text{o}_\text{cell} = -0.76\,\text{V}$$

Question 1

Which of the following statements correctly describes the relationship between $$E^	ext{o}_	ext{cell}$$, $$\Delta G^	ext{o}$$, and $$K$$ for a spontaneous electrochemical reaction under standard conditions?

Accepted Answer

$$E^	ext{o}_	ext{cell} \u003e 0$$, $$\Delta G^	ext{o}  1$$

Question 2

Given the following half-reactions and their standard reduction potentials:

$$	ext{Ni}^{2+}(aq) + 2e^- ightarrow 	ext{Ni}(s)$$  $$E^	ext{o} = -0.23\,	ext{V}$$
$$	ext{Al}^{3+}(aq) + 3e^- ightarrow 	ext{Al}(s)$$  $$E^	ext{o} = -1.66\,	ext{V}$$

What is the standard cell potential ($$E^	ext{o}_	ext{cell}) $$for the reaction:

$$3	ext{Ni}^{2+}(aq) + 2	ext{Al}(s) ightarrow 3	ext{Ni}(s) + 2	ext{Al}^{3+}(aq)$$?

Accepted Answer

$$E^	ext{o}_	ext{cell} = +1.43\,	ext{V}$$

Question 3

Using the Nernst equation, calculate the cell potential for the following reaction at $$25^\circC $$when $$[	ext{Cu}^{2+}] = 2.0\,	ext{M}$$ and $$[	ext{Zn}^{2+}] = 0.010\,	ext{M}$$:

$$	ext{Cu}^{2+}(aq) + 	ext{Zn}(s) ightarrow 	ext{Cu}(s) + 	ext{Zn}^{2+}(aq)$$

Given $$E^	ext{o}_	ext{cell} = 1.10\,	ext{V}.$$

Accepted Answer

$$E_	ext{cell} = 1.10 + 0.0592 \log \left( \frac{0.010}{2.0} ight)$$

Question 4

A voltaic cell is constructed using the following half-cells:

$$	ext{Ag}^{+}(aq) + e^- ightarrow 	ext{Ag}(s)$$  $$E^	ext{o} = +0.80\,	ext{V}$$
$$	ext{Au}^{3+}(aq) + 3e^- ightarrow 	ext{Au}(s)$$  $$E^	ext{o} = +1.50\,	ext{V}$$

Which metal acts as the anode?

Accepted Answer

Silver (Ag)

Question 5

For the reaction $$3	ext{Ni}^{2+}(aq) + 2	ext{Al}(s) ightarrow 3	ext{Ni}(s) + 2	ext{Al}^{3+}(aq)$$, how much work (in kJ) can be obtained if $$E^	ext{o}_	ext{cell} = 1.43\,	ext{V}$$ and $$n = 6$$? Use $$F = 96,485\,	ext{C/mol}.$$

Accepted Answer

$$-830\,	ext{kJ}$$

Question 6

Which equation correctly relates the standard free energy change to the standard cell potential?

Accepted Answer

$$\Delta G^	ext{o} = -nFE^	ext{o}_	ext{cell}$$

Question 7

A concentration cell is set up with $$[	ext{Cu}^{2+}] = 1.0\,	ext{M} in $$one half-cell and $$[	ext{Cu}^{2+}] = 0.10\,	ext{M} in $$the other. What is the direction of electron flow?

Accepted Answer

From the 0.10 M cell to the 1.0 M cell

Question 8

Which of the following is true for a cell where $$Q = 0.0010$$ and $$K = 0.10$$?

Accepted Answer

$$E_	ext{cell} is $$positive and $$E^	ext{o}_	ext{cell} is $$negative

Question 9

In a redox reaction, which species is oxidized?

Accepted Answer

The species that loses electrons

Question 10

Which equation is used to calculate the equilibrium constant $$K$$ from the standard cell potential $$E^	ext{o}_	ext{cell}$$?

Accepted Answer

$$E^	ext{o}_	ext{cell} = \frac{0.0592}{n} \log K$$

Question 11

For the reaction $$	ext{Zn}(s) + 2	ext{H}^+(aq) ightarrow 	ext{Zn}^{2+}(aq) + 	ext{H}_2(g)$$, what is the standard cell potential if the standard hydrogen electrode (SHE) is used as the cathode?

Accepted Answer

$$E^	ext{o}_	ext{cell} = -0.76\,	ext{V}$$

Question 12

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

Accepted Answer

It maintains electrical neutrality by allowing ion flow

Question 13

A neuron transmits signals via changes in membrane potential. Which equation is used to calculate the membrane potential due to potassium ion concentration differences?

Accepted Answer

$$E = E^	ext{o} - \frac{RT}{nF} \ln \left( \frac{[K^+]_{	ext{inside}}}{[K^+]_{	ext{outside}}} ight)$$

Question 14

Which of the following is true for a reaction with $$E^	ext{o}_	ext{cell} \u003c 0$$?

Accepted Answer

The equilibrium constant $$K \u003c 1$$

Question 15

For the cell $$	ext{Cd}(s) | 	ext{Cd}^{2+}(aq, 0.60\,	ext{M}) || 	ext{Fe}^{2+}(aq, 0.010\,	ext{M}) | 	ext{Fe}(s)$$, calculate the cell potential using the Nernst equation. Given $$E^	ext{o}_	ext{cell} = -0.04\,	ext{V}$$ and $$n = 2.$$

Accepted Answer

$$E_	ext{cell} = -0.04 + \frac{0.0592}{2} \log \left( \frac{0.010}{0.60} ight)$$

Question 16

Which of the following is the correct cell notation for a voltaic cell constructed from $$	ext{Ag}^{+}(aq)$$ and $$	ext{Au}^{3+}(aq)$$ half-cells?

Accepted Answer

$$	ext{Ag}(s) | 	ext{Ag}^{+}(aq, 1.0\,	ext{M}) || 	ext{Au}^{3+}(aq, 1.0\,	ext{M}) | 	ext{Au}(s)$$

Question 17

What is the equilibrium constant $$K$$ for the redox reaction between $$	ext{Al}(s)$$ and $$	ext{Ni}^{2+}(aq)$$, given $$E^	ext{o}_	ext{cell} = 1.43\,	ext{V}$$ and $$n = 6$$?

Accepted Answer

$$K = 10$$^{14}$$

Question 18

Which of the following best describes a concentration cell?

Accepted Answer

A cell in which voltage is generated because of differences in concentrations

Electrochemistry: Cell Potentials, Redox Reactions, and Equilibrium (Chapter 19 Study Notes)

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드