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 $g \ mol^{-1}$ - $Na : 23$; $N : 14$; $O : 16$]

What is the weight in $g$ of potassium chlorate $(KClO_3)$ required to produce the oxygen needed for the complete combustion of $84 \ L$ of $CO$ at $N.T.P$?

$25 \ mL$ of a solution of $Na_2CO_3$ having a specific gravity of $1.25$ required $32.9 \ mL$ of a solution of $HCl$ containing $109.5 \ g$ of the acid per litre for complete neutralization. Calculate the volume of $0.84 \ N$ $H_2SO_4$ that will be completely neutralized by $125 \ g$ of the $Na_2CO_3$ solution (in $mL$).

The normality of $2 \ M$ sulphuric acid is: (in $N$)

$3 \ L$ 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.

Combustion of glucose $(C_6H_{12}O_6)$ produces $CO_2$ and water. The amount of oxygen (in $g$) required for the complete combustion of $900 \ g$ of glucose is:
[Molar mass of glucose in $g \ mol^{-1} = 180$]