How many atoms of calcium will be deposited at the cathode when a current of $25 \ mA$ is passed through a $CaCl_2$ solution for $60 \ s$?

Copper is to be electrodeposited on a nickel block of $(20 \times 5) \ cm^2$ area by using $CuSO_4$ as electrolyte. How much quantity of electricity is needed to deposit a $3.6 \ \mu m$ layer of copper (in $C$)? [Atomic weight of $Cu = 63.5 \ g \ mol^{-1}$,Density of $Cu = 8.9 \ g/cm^3$]

One litre solution of $MgCl_2$ is electrolyzed completely by passing a current of $1 \ A$ for $16 \ min \ 5 \ sec$. The original concentration of $MgCl_2$ solution was (Atomic mass of $Mg = 24$)

Match List $I$ with List $II$.

List $I$ (Conversion)	List $II$ (Number of Faraday required)
$A$. $1 \text{ mol of } H_2O \text{ to } O_2$	$I$. $3F$
$B$. $1 \text{ mol of } MnO_4^- \text{ to } Mn^{2+}$	$II$. $2F$
$C$. $1.5 \text{ mol of } Ca \text{ from molten } CaCl_2$	$III$. $1F$
$D$. $1 \text{ mol of } FeO \text{ to } Fe_2O_3$	$IV$. $5F$

Choose the correct answer from the options given below:

When an electric current is passed through acidulated water,$112 \ mL$ of hydrogen gas at $N.T.P.$ collects at the cathode in $965 \ seconds$. The current passed,in amperes,is:

Salts of $A$ (atomic weight $8$),$B$ (atomic weight $18$) and $C$ (atomic weight $50$) were electrolysed under identical conditions using the same quantity of electricity. It was found that $2.4 \ g$ of $A$ was deposited,the weight of $B$ and $C$ deposited are $1.8 \ g$ and $7.5 \ g$ respectively. The valences of $A$,$B$ and $C$ are,respectively,