Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through aqueous…
Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through aqueous solution of aluminium ion is
$30 \mathrm{~s}$
$10 \mathrm{~s}$
$30,000 \mathrm{~s}$
$10,000 \mathrm{~s}$.
Solution
$ \mathrm{Al}^{3+}+3 e^{-} \rightarrow \mathrm{Al}$
For deposition of $1 \mathrm{~g}$ equivalent $\equiv 96500 \mathrm{C}$
For deposition of 1 millimole $\equiv 96.500 \mathrm{C}$
As $Q=I t \Rightarrow t=\frac{Q}{I}=\frac{96.5}{9.65}=10 \mathrm{~s}$