Which of the following changes occurs during the discharging of lead accumulator?
Which of the following changes occurs during the discharging of lead accumulator?
$\mathrm{Pb}_{(s)}$ is reduced
$\mathrm{H}_2 \mathrm{SO}_4$ is consumed
$\mathrm{PbSO}_4$ is consumed
$\mathrm{PbO}_2$ is produced
Solution
During discharge, the following reaction occurs:
$\mathrm{Pb}_{(\mathrm{s})}+\mathrm{PbO}_{2(\mathrm{~s})}+2 \mathrm{H}_2 \mathrm{SO}_{4(\mathrm{aq})} \rightarrow 2 \mathrm{PbSO}_{4(\mathrm{~s})}+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l}}$ As the cell operates to generate current, $\mathrm{H}_2 \mathrm{SO}_4$ is consumed.