$A$ $250 \, mL$ solution of $Na_2CO_3$ contains $2.65 \, g$ of $Na_2CO_3$. If $10 \, mL$ of this solution is taken and diluted with distilled water up to $0.1 \, L$,what will be the molarity of the resulting solution (in $, M$)?

The weight of $1 \ L$ of a hydrocarbon is more than that of $1 \ L$ of $CO_2$ at the same temperature and pressure. What is the molecular formula of the hydrocarbon?

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.)

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

An average person needs about $10000 \ kJ$ energy per day. The amount of glucose (molar mass $= 180.0 \ g \ mol^{-1}$) needed to meet this energy requirement is $..... \ g$.
(Nearest integer)
(Use : $\Delta_{c} H(\text{glucose}) = -2700 \ kJ \ mol^{-1}$)

The density of $SO_2$ at $STP$ is ......... $g/L$.