Give the different types of batteries and explain the construction and working of each type of battery.

The standard potentials for some electrodes are as follows. Arrange the metals in an increasing order of their reducing power.

$$\begin{gathered} \left(1\right) {\mathrm{K}}^{+}/\mathrm{K} =-2.93\mathrm{V} \left(2\right) {\mathrm{Ag}}^{+}/\mathrm{Ag} =0.80\mathrm{V} \left(3\right) {\mathrm{Cu}}^{2+}/\mathrm{Cu} =0.34\mathrm{V} \\ \left(4\right) {\mathrm{Mg}}^{2+}/\mathrm{Mg} =-2.37\mathrm{V} \left(5\right) {\mathrm{Cr}}^{3+}/\mathrm{Cr} =-0.74\mathrm{V} \left(6\right) {\mathrm{Fe}}^{2+}/\mathrm{Fe} =-0.44\mathrm{V} \end{gathered}$$

Calculate the emf of a cell at 25^oC. $\mathrm{Cr}/{\mathrm{Cr}}^{3+}\left(0.1\mathrm{M}\right)//{\mathrm{Fe}}^{2+}\left(0.01\mathrm{M}\right)/\mathrm{Fe}$

Given that ${\mathrm{E}}_{\mathrm{Cr}/{\mathrm{Cr}}^{+3}}^{\mathrm{o}} =-0.74\mathrm{V}$and ${\mathrm{E}}_{{\mathrm{Fe}}^{2+}/\mathrm{Fe}}^{\mathrm{o}} =-0.44\mathrm{V}$

Determine $∆{\mathrm{G}}^{°}$ for the button cells used in the watches. The cell reaction is

 $\mathrm{Zn}\left(\mathrm{s}\right) + {\mathrm{Ag}}_2\mathrm{O}\left(\mathrm{s}\right) +{\mathrm{H}}_2\mathrm{O} \to {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right) + 2\mathrm{Ag}\left(\mathrm{s}\right) + 2{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$,  

${\mathrm{E}}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\mathrm{o}} =+0.80\mathrm{V}; {\mathrm{E}}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{\mathrm{o}} =-0.76\mathrm{V}$

Calculate the emf of the cell consisting the following half cells. $\mathrm{Al}/{\mathrm{Al}}^{3+}\left(0.001\mathrm{M}\right)//\mathrm{Ni}/{\mathrm{Ni}}^{2+}\left(0.50\mathrm{M}\right)$

Given that  ${\mathrm{E}}_{{\mathrm{Ni}}^{2+}/\mathrm{Ni}}^{\mathrm{o}} =-0.25\mathrm{V}$and ${\mathrm{E}}_{{\mathrm{Al}}^{3+}/\mathrm{Al}}^{\mathrm{o}} =-1.66\mathrm{V}$, $\log \left(8\times {10}^{-6} =-5.0969\right)$

Determine the values of ${\mathrm{K}}_{\mathrm{c}}$ for the following reactions

$\mathrm{Ni}\left(\mathrm{s}\right) + 2{\mathrm{Ag}}^{+}\left(\mathrm{aq}\right) \to {\mathrm{Ni}}^{2+}\left(\mathrm{aq}\right) + \mathrm{Ag}\left(\mathrm{s}\right) ; {\mathrm{E}}^{\mathrm{o}} = 1.05\mathrm{V}$

Calculate the potential of the half cell containing $0.1\mathrm{M} {\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\left(\mathrm{aq}\right), 0.2\mathrm{M} {\mathrm{Cr}}^{3+}\left(\mathrm{aq}\right) \mathrm{and} 1.0\times {10}^{-4}\mathrm{M} {\mathrm{H}}^{+}.$ The half cell reaction is

${\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-} \left(\mathrm{aq}\right) + 14{\mathrm{H}}^{+}\left(\mathrm{aq}\right) +6{\mathrm{e}}^{-} \to 2{\mathrm{Cr}}^{3+}\left(\mathrm{aq}\right) + 7{\mathrm{H}}_2\mathrm{O}$,   ${\mathrm{E}}_{\mathrm{cell}}^{\mathrm{o}} = 1.33\mathrm{V}$.

Calculate ${\mathrm{K}}_{\mathrm{c}}$ for the reaction at 298K  $\mathrm{Zn}\left(\mathrm{s}\right) + {\mathrm{Cu}}^{2+} \left(\mathrm{aq}\right) \rightleftharpoons {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right) + \mathrm{Cu}\left(\mathrm{s}\right)$

$∆{\mathrm{G}}^{\mathrm{o}} =-212.30 \mathrm{kJ}/\mathrm{mole}, {\mathrm{E}}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{\mathrm{o}} =-0.76\mathrm{V}, {\mathrm{E}}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^{\mathrm{o}} =0.34\mathrm{V}$