00. Electrode Potential
ELECTROCHEMISTRY

275805 If the standard electrode potential for a cell is $2 \mathrm{~V}$ at $300 \mathrm{~K}$, the equilibrium constant (K) for the reaction
$\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(\mathrm{aq}) \rightleftharpoons \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$
at $300 \mathrm{~K}$ is approximately
$\left(\mathrm{R}=8 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}, \mathrm{~F}=\mathbf{9 6 0 0 0 \mathrm { C } \mathrm { mol } ^ { - 1 } )}\right.$

1 $\mathrm{e}^{-160}$
2 $e^{160}$
3 $\mathrm{e}^{-80}$
4 $\mathrm{e}^{320}$
ELECTROCHEMISTRY

275806 Consider the following reduction processes:
$\mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.76 \mathrm{~V}$
$\mathrm{Ca}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ca}(\mathrm{s}) ; \mathrm{E}^{0}=-2.87 \mathrm{~V}$
$\mathrm{Mg}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mg}(\mathrm{s}) ; \mathrm{E}^{\mathrm{o}}=-2.36 \mathrm{~V}$
$\mathrm{Ni}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.25 \mathrm{~V}$
The reducing power of the metals increases in the order

1 $\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}<\mathrm{Ca}$
2 $\mathrm{Ni}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ca}$
3 $\mathrm{Ca}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}$
4 $\mathrm{Ca}<\mathrm{Mg}<\mathrm{Zn}<\mathrm{Ni}$
ELECTROCHEMISTRY

275807 In the cell,
$\operatorname{Pt}(\mathrm{s}) \mid \mathrm{H}_{2}$ (g, 1 bar) $ \vert\mathrm{HCl} \vert(\mathrm{aq}) \mathrm{AgCl} \mid(\mathrm{s})$
$ \vert\operatorname{Ag}(\mathrm{s}) \vert \operatorname{Pt}(\mathrm{s})$ the cell potential is $0.92 \mathrm{~V}$ when a $10^{-6}$ modal $\mathrm{HCl}$ solution is used. The standard electrode potential of $\left(\mathrm{AgCl} / \mathrm{Ag}, \mathrm{Cl}^{-}\right)$electrode is
$\left\{\text { Given, } \frac{2.303 R T}{F}=0.06 \mathrm{~V} \text { at } 298 \mathrm{~K}\right\}$

1 $0.40 \mathrm{~V}$
2 $0.20 \mathrm{~V}$
3 $0.94 \mathrm{~V}$
4 $0.76 \mathrm{~V}$
ELECTROCHEMISTRY

275810 Given, $\mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{0}=-0.72 \mathrm{~V}, \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{0}=-0.42 \mathrm{~V}$.
The potential for the cell
$\mathrm{Cr}\left \vert\mathrm{Cr}^{3+}(0.1 \mathrm{M}) \ \vert \mathrm{Fe}^{2+}(0.01 \mathrm{M})\right \vert \mathrm{Fe}$ is

1 $-0.339 \mathrm{~V}$
2 $-0.26 \mathrm{~V}$
3 $0.26 \mathrm{~V}$
4 $0.3 \mathrm{~V}$
ELECTROCHEMISTRY

275805 If the standard electrode potential for a cell is $2 \mathrm{~V}$ at $300 \mathrm{~K}$, the equilibrium constant (K) for the reaction
$\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(\mathrm{aq}) \rightleftharpoons \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$
at $300 \mathrm{~K}$ is approximately
$\left(\mathrm{R}=8 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}, \mathrm{~F}=\mathbf{9 6 0 0 0 \mathrm { C } \mathrm { mol } ^ { - 1 } )}\right.$

1 $\mathrm{e}^{-160}$
2 $e^{160}$
3 $\mathrm{e}^{-80}$
4 $\mathrm{e}^{320}$
ELECTROCHEMISTRY

275806 Consider the following reduction processes:
$\mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.76 \mathrm{~V}$
$\mathrm{Ca}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ca}(\mathrm{s}) ; \mathrm{E}^{0}=-2.87 \mathrm{~V}$
$\mathrm{Mg}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mg}(\mathrm{s}) ; \mathrm{E}^{\mathrm{o}}=-2.36 \mathrm{~V}$
$\mathrm{Ni}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.25 \mathrm{~V}$
The reducing power of the metals increases in the order

1 $\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}<\mathrm{Ca}$
2 $\mathrm{Ni}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ca}$
3 $\mathrm{Ca}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}$
4 $\mathrm{Ca}<\mathrm{Mg}<\mathrm{Zn}<\mathrm{Ni}$
ELECTROCHEMISTRY

275807 In the cell,
$\operatorname{Pt}(\mathrm{s}) \mid \mathrm{H}_{2}$ (g, 1 bar) $ \vert\mathrm{HCl} \vert(\mathrm{aq}) \mathrm{AgCl} \mid(\mathrm{s})$
$ \vert\operatorname{Ag}(\mathrm{s}) \vert \operatorname{Pt}(\mathrm{s})$ the cell potential is $0.92 \mathrm{~V}$ when a $10^{-6}$ modal $\mathrm{HCl}$ solution is used. The standard electrode potential of $\left(\mathrm{AgCl} / \mathrm{Ag}, \mathrm{Cl}^{-}\right)$electrode is
$\left\{\text { Given, } \frac{2.303 R T}{F}=0.06 \mathrm{~V} \text { at } 298 \mathrm{~K}\right\}$

1 $0.40 \mathrm{~V}$
2 $0.20 \mathrm{~V}$
3 $0.94 \mathrm{~V}$
4 $0.76 \mathrm{~V}$
ELECTROCHEMISTRY

275810 Given, $\mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{0}=-0.72 \mathrm{~V}, \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{0}=-0.42 \mathrm{~V}$.
The potential for the cell
$\mathrm{Cr}\left \vert\mathrm{Cr}^{3+}(0.1 \mathrm{M}) \ \vert \mathrm{Fe}^{2+}(0.01 \mathrm{M})\right \vert \mathrm{Fe}$ is

1 $-0.339 \mathrm{~V}$
2 $-0.26 \mathrm{~V}$
3 $0.26 \mathrm{~V}$
4 $0.3 \mathrm{~V}$
ELECTROCHEMISTRY

275805 If the standard electrode potential for a cell is $2 \mathrm{~V}$ at $300 \mathrm{~K}$, the equilibrium constant (K) for the reaction
$\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(\mathrm{aq}) \rightleftharpoons \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$
at $300 \mathrm{~K}$ is approximately
$\left(\mathrm{R}=8 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}, \mathrm{~F}=\mathbf{9 6 0 0 0 \mathrm { C } \mathrm { mol } ^ { - 1 } )}\right.$

1 $\mathrm{e}^{-160}$
2 $e^{160}$
3 $\mathrm{e}^{-80}$
4 $\mathrm{e}^{320}$
ELECTROCHEMISTRY

275806 Consider the following reduction processes:
$\mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.76 \mathrm{~V}$
$\mathrm{Ca}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ca}(\mathrm{s}) ; \mathrm{E}^{0}=-2.87 \mathrm{~V}$
$\mathrm{Mg}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mg}(\mathrm{s}) ; \mathrm{E}^{\mathrm{o}}=-2.36 \mathrm{~V}$
$\mathrm{Ni}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.25 \mathrm{~V}$
The reducing power of the metals increases in the order

1 $\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}<\mathrm{Ca}$
2 $\mathrm{Ni}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ca}$
3 $\mathrm{Ca}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}$
4 $\mathrm{Ca}<\mathrm{Mg}<\mathrm{Zn}<\mathrm{Ni}$
ELECTROCHEMISTRY

275807 In the cell,
$\operatorname{Pt}(\mathrm{s}) \mid \mathrm{H}_{2}$ (g, 1 bar) $ \vert\mathrm{HCl} \vert(\mathrm{aq}) \mathrm{AgCl} \mid(\mathrm{s})$
$ \vert\operatorname{Ag}(\mathrm{s}) \vert \operatorname{Pt}(\mathrm{s})$ the cell potential is $0.92 \mathrm{~V}$ when a $10^{-6}$ modal $\mathrm{HCl}$ solution is used. The standard electrode potential of $\left(\mathrm{AgCl} / \mathrm{Ag}, \mathrm{Cl}^{-}\right)$electrode is
$\left\{\text { Given, } \frac{2.303 R T}{F}=0.06 \mathrm{~V} \text { at } 298 \mathrm{~K}\right\}$

1 $0.40 \mathrm{~V}$
2 $0.20 \mathrm{~V}$
3 $0.94 \mathrm{~V}$
4 $0.76 \mathrm{~V}$
ELECTROCHEMISTRY

275810 Given, $\mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{0}=-0.72 \mathrm{~V}, \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{0}=-0.42 \mathrm{~V}$.
The potential for the cell
$\mathrm{Cr}\left \vert\mathrm{Cr}^{3+}(0.1 \mathrm{M}) \ \vert \mathrm{Fe}^{2+}(0.01 \mathrm{M})\right \vert \mathrm{Fe}$ is

1 $-0.339 \mathrm{~V}$
2 $-0.26 \mathrm{~V}$
3 $0.26 \mathrm{~V}$
4 $0.3 \mathrm{~V}$
ELECTROCHEMISTRY

275805 If the standard electrode potential for a cell is $2 \mathrm{~V}$ at $300 \mathrm{~K}$, the equilibrium constant (K) for the reaction
$\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(\mathrm{aq}) \rightleftharpoons \mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$
at $300 \mathrm{~K}$ is approximately
$\left(\mathrm{R}=8 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}, \mathrm{~F}=\mathbf{9 6 0 0 0 \mathrm { C } \mathrm { mol } ^ { - 1 } )}\right.$

1 $\mathrm{e}^{-160}$
2 $e^{160}$
3 $\mathrm{e}^{-80}$
4 $\mathrm{e}^{320}$
ELECTROCHEMISTRY

275806 Consider the following reduction processes:
$\mathrm{Zn}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Zn}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.76 \mathrm{~V}$
$\mathrm{Ca}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ca}(\mathrm{s}) ; \mathrm{E}^{0}=-2.87 \mathrm{~V}$
$\mathrm{Mg}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mg}(\mathrm{s}) ; \mathrm{E}^{\mathrm{o}}=-2.36 \mathrm{~V}$
$\mathrm{Ni}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Ni}(\mathrm{s}) ; \mathrm{E}^{\mathbf{0}}=-0.25 \mathrm{~V}$
The reducing power of the metals increases in the order

1 $\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}<\mathrm{Ca}$
2 $\mathrm{Ni}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ca}$
3 $\mathrm{Ca}<\mathrm{Zn}<\mathrm{Mg}<\mathrm{Ni}$
4 $\mathrm{Ca}<\mathrm{Mg}<\mathrm{Zn}<\mathrm{Ni}$
ELECTROCHEMISTRY

275807 In the cell,
$\operatorname{Pt}(\mathrm{s}) \mid \mathrm{H}_{2}$ (g, 1 bar) $ \vert\mathrm{HCl} \vert(\mathrm{aq}) \mathrm{AgCl} \mid(\mathrm{s})$
$ \vert\operatorname{Ag}(\mathrm{s}) \vert \operatorname{Pt}(\mathrm{s})$ the cell potential is $0.92 \mathrm{~V}$ when a $10^{-6}$ modal $\mathrm{HCl}$ solution is used. The standard electrode potential of $\left(\mathrm{AgCl} / \mathrm{Ag}, \mathrm{Cl}^{-}\right)$electrode is
$\left\{\text { Given, } \frac{2.303 R T}{F}=0.06 \mathrm{~V} \text { at } 298 \mathrm{~K}\right\}$

1 $0.40 \mathrm{~V}$
2 $0.20 \mathrm{~V}$
3 $0.94 \mathrm{~V}$
4 $0.76 \mathrm{~V}$
ELECTROCHEMISTRY

275810 Given, $\mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Cr}}^{0}=-0.72 \mathrm{~V}, \mathrm{E}_{\mathrm{Fe}^{2+} / \mathrm{Fe}}^{0}=-0.42 \mathrm{~V}$.
The potential for the cell
$\mathrm{Cr}\left \vert\mathrm{Cr}^{3+}(0.1 \mathrm{M}) \ \vert \mathrm{Fe}^{2+}(0.01 \mathrm{M})\right \vert \mathrm{Fe}$ is

1 $-0.339 \mathrm{~V}$
2 $-0.26 \mathrm{~V}$
3 $0.26 \mathrm{~V}$
4 $0.3 \mathrm{~V}$