The Molarity $(M)$ of an aqueous solution containing $5.85 \ g$ of $NaCl$ in $500 \ mL$ water is :
(Given : Molar Mass $Na: 23$ and $Cl: 35.5 \ g \ mol^{-1}$ )

How many litres of oxygen (at $STP$) are required for complete combustion of $39 \ g$ of liquid benzene?
(Atomic weights: $C=12, O=16, H=1$)

Consider the reaction
$4 HNO_{3(\ell)} + 3 KCl_{(s)} \rightarrow Cl_{2(g)} + NOCl_{(g)} + 2 H_{2}O_{(g)} + 3 KNO_{3(s)}$
The amount of $HNO_{3}$ required to produce $110.0 \ g$ of $KNO_{3}$ is $...... \ g$.
(Given: Atomic masses of $H, O, N$ and $K$ are $1, 16, 14$ and $39$ respectively.)

How many moles of $H_2O_2$ are required to decolorize $1$ mole of $KMnO_4$ (in $.5$)?

How many liters of $CO_2$ gas are released at $STP$ upon the complete decomposition of $9.85 \ g$ of $BaCO_3$ (Atomic mass of $Ba = 137$)?

If the density of methanol is $0.793 \ kg \ L^{-1}$,what volume is needed to prepare $2.5 \ L$ of a $0.25 \ M$ solution (in $mL$)?