The value of current required to deposit $0.972 \ g$ of chromium in $3 \ hours$ if the $E.C.E.$ of chromium is $0.00018 \ g \ C^{-1}$,is ............ $A$.

Two electrolytic cells,one containing acidified ferrous chloride $(FeCl_2)$ and the other containing acidic ferric chloride $(FeCl_3)$,are connected in series. When an electric current is passed through the cells,what is the ratio of iron deposited at the cathodes in the two cells?

If $96500 \ C$ of electricity liberates one gram equivalent of any substance,the time taken for a current of $0.15 \ A$ to deposit $20 \ mg$ of copper from a solution of copper sulphate is (Chemical equivalent of copper = $32$).

$3.17 \ g$ of a substance is deposited by a current of $0.1 \ mol$ of electrons. What is the equivalent weight of the substance?

How many faraday are needed to reduce a mole of $MnO_4^-$ to $Mn^{2+}$?

The time required to remove electrolytically one fourth of $Ag^+$ from $0.2 \ L$ of $0.1 \ M \ AgCl$ solution by a current of $0.1 \ A$ is approximately $.......... \ min$.