$4.4 \ g$ of an unknown gas occupies $2.24 \ L$ of volume at standard temperature and pressure. The gas may be

$A$ solution contains $1.2046 \times 10^{24}$ hydrochloric acid molecules in one $dm^3$ of the solution. The strength of the solution is .......... $N$.

The $NaNO_3$ weighed out to make $50 \ mL$ of an aqueous solution containing $70.0 \ mg$ $Na^{+}$ per $mL$ is $...... \ g$.
(Rounded off to the nearest integer) [Given : Atomic weight in $g \ mol^{-1}$ - $Na : 23$; $N : 14$; $O : 16$]

The number of molecules of $CO_2$ liberated by the complete combustion of $0.1 \ mol$ of graphite in air is

When $5 \, mL$ of $N \, HCl$,$20 \, mL$ of $N/2 \, H_2SO_4$,and $30 \, mL$ of $N/3 \, HNO_3$ are mixed together and the volume is made up to $1 \, L$,the normality of the resulting solution is:

$3 \ L$ mixture of $C_2H_6$ and $C_3H_8$ produces $8 \ L$ of $CO_2$ upon complete combustion. Find the volume of $C_2H_6$ in the mixture.