When an electric current is passed through acidified water,$112 \ mL$ of hydrogen gas at $N.T.P.$ was collected at the cathode in $965 \ seconds$. The current passed,in ampere,is

In two separate experiments,the same quantity of electricity was passed through silver and gold solutions. The amounts of $Ag$ and $Au$ deposited are $2.15 \ g$ and $1.31 \ g$,respectively. The valency of gold is [Atomic mass of $Ag = 107.9$; $Au = 197$].

The density and equivalent weight of a metal are $10.5\, g\, cm^{-3}$ and $100$,respectively. The time required for a current of $3\, A$ to deposit a $0.005\, mm$ thick layer of the same metal on an area of $80\, cm^2$ is closest to $....\, s$

How many $L$ of chlorine gas will be deposited at $NTP$ when a current of $100 \, A$ is passed through molten $NaCl$ for $5 \, hours$?

Aluminium oxide may be electrolysed at $1000 \, ^\circ C$ to furnish aluminium metal (At. Mass $= 27 \, amu$; $1 \, F = 96,500 \, C$). The cathode reaction is $Al^{3+} + 3e^- \to Al^0$. To prepare $5.12 \, kg$ of aluminium metal by this method would require:

The charge required for the reduction of $1 \ \text{mole}$ of $MnO_4^{-}$ to $MnO_2$ is (in $F$)