17.3 Electrode and Cell Potentials

Calculate the standard cell potential for each reaction below, and note whether the reaction is spontaneous under standard state conditions.

(a) $\text{Mg} \left(s\right) + \text{Ni}^{2+} \left(a q\right) \rightarrow \text{Mg}^{2+} \left(a q\right) + \text{Ni} \left(s\right)$

(b) $2 \text{Ag}^{+} \left(a q\right) + \text{Cu} \left(s\right) \rightarrow \text{Cu}^{2+} \left(a q\right) + \text{2Ag} \left(s\right)$

(c) $\text{Mn} \left(s\right) + \text{Sn}(\text{NO}_{3} \left.\right)_{2} \left(a q\right) \rightarrow \text{Mn}(\text{NO}_{3} \left.\right)_{2} \left(a q\right) + \text{Sn} \left(s\right)$

(d) $3 \text{Fe}(\text{NO}_{3} \left.\right)_{2} \left(a q\right) + \text{Au}(\text{NO}_{3} \left.\right)_{3} \left(a q\right) \rightarrow \text{3Fe}(\text{NO}_{3} \left.\right)_{3} \left(a q\right) + \text{Au} \left(s\right)$

Write the balanced cell reaction for the cell schematic below, calculate the standard cell potential, and note whether the reaction is spontaneous under standard state conditions.

$\text{Cu} \left(s\right) \mid \text{Cu}^{2+} \left(a q\right) ║ \text{Au}^{3+} \left(a q\right) \mid \text{Au} \left(s\right)$

Determine the cell reaction and standard cell potential at 25 °C for a cell made from an anode half-cell containing a cadmium electrode in 1 M cadmium nitrate and a cathode half-cell consisting of an aluminum electrode in 1 M aluminum nitrate solution. Is the reaction spontaneous at standard conditions?