For the electrolytic decomposition of $18 \ g$ of $H_2O$,how many hours of current at $3 \ A$ must be passed?

The current flowing in a copper voltameter is $1.6 \ A$. The number of $Cu^{2+}$ ions deposited at the cathode per minute are

In a copper voltameter experiment,current is decreased to one-fourth of the initial value but it is passed for four times the earlier duration. The amount of copper deposited will be:

The same quantity of electricity was passed through solutions of salts of elements $X$,$Y$,and $Z$ with atomic masses $7$,$27$,and $48$ respectively. The masses of $X$,$Y$,and $Z$ deposited were $2.1 \ g$,$2.7 \ g$,and $7.2 \ g$ respectively. The valencies of $X$,$Y$,and $Z$ respectively are:

When a current of $10800 \ C$ is passed through an electrolyte,$2.977 \ g$ of a metal is deposited. If the molar mass of the metal is $106.4 \ g \ mol^{-1}$,what is the charge on the metal cation?

$Al_2O_3$ is reduced by electrolysis at low potentials and high currents. If $4.0 \times 10^4$ amperes of current is passed through molten $Al_2O_3$ for $6$ hours,what mass of aluminium is produced? (Assume $100\%$ current efficiency,at. mass of $Al = 27 \ g \ mol^{-1}$).