The emf of a particular voltaic cell with the cell reaction $\mathrm{Hg}_{2}^{2+}+\mathrm{H}_{2}…

The emf of a particular voltaic cell with the cell reaction $\mathrm{Hg}_{2}^{2+}+\mathrm{H}_{2} ightleftharpoons 2 \mathrm{Hg}+2 \mathrm{H}^{+}$ is $0.65$
V. The maximum electrical work of this cell when $0.5 \mathrm{~g}$ of $\mathrm{H}_{2}$ is consumed.
  1. $-3.12 \times 10^{4} \mathrm{~J}$
  2. $-1.25 \times 10^{5} \mathrm{~J}$
  3. $\quad 25.0 \times 10^{6} \mathrm{~J}$
  4. None of these

Solution

$\quad W_{\max }=-n \cdot F E$
$W_{\max }=-2 \times 96500 \times 0.65=-1.25 \times 10^{5} \mathrm{~J}$
$0.5 \mathrm{~g} \mathrm{H}_{2}=0.25 \mathrm{~mole}$
Hence $W_{\max }$
$=-1.25 \times 10^{5} \times 0.25=-3.12 \times 10^{4} \mathrm{~J}$

Asked in: JEE-TOPICTESTS-CHEMISTRY

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