In an experiment,$0.04 \ F$ was passed through $400 \ mL$ of a $1 \ M$ solution of $NaCl$. What would be the $pH$ of the solution after the electrolysis? (Change in volume will be negligible)

$A$ $200 \ W, 100 \ V$ bulb is connected in series with an electrolytic cell. If an aqueous solution of an $Sn$-salt is electrolysed for $5 \ hrs$,$11.1 \ g$ of $Sn$ gets deposited. The chemical formula of the compound is (Given atomic weight of $Sn$ is $118.7 \ g \ mol^{-1}$).

$A$ certain current liberated $0.504 \ g$ of hydrogen in $2 \ hours$. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution?

Cells $A$ and $B$ contain aqueous solutions of ferrous chloride $(FeCl_2)$ and ferric chloride $(FeCl_3)$ respectively. If the same quantity of electricity is passed through both cells, what is the ratio of the mass of iron deposited in cell $A$ to that in cell $B$?

The chemical equivalent of silver is $108$. If the current in a silver voltameter is $2 \ A$,the time required to deposit $27 \ g$ of silver will be ............ $hrs$.

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: