What is the mole fraction of water in $10\%$ by weight $(w/w)$ of aqueous urea solution? [Given: Molar mass of $H, O, C$ and $N$ are $1, 16, 12$ and $14 \text{ g mol}^{-1}$ respectively.]

The density of $3 \ M$ solution of $NaCl$ is $1.0 \ g \ mL^{-1}$. Molality of the solution is $...... \times 10^{-2} \ m$. (Nearest integer). Given: Molar mass of $Na$ and $Cl$ is $23$ and $35.5 \ g \ mol^{-1}$ respectively.

The amount of sugar $(C_{12}H_{22}O_{11})$ required to prepare $2 \ L$ of its $0.1 \ M$ aqueous solution is ............... $g$.

Find out the molality of a solution prepared by dissolving $2.89 \ g$ of $NaCl$ in $0.159 \ L$ of water. The density of water is $1.00 \ g / mL$. (in $m$)

Equal volumes of liquid $A$ $(d = 0.8 \ g/mL)$ and liquid $B$ $(d = 1.2 \ g/mL)$ are mixed to form a solution. Calculate the mole fraction of $A$ in the solution $(M_A = 16, M_B = 32)$.

$100 \ mL$ of $\frac{M}{10} \ Ca(NO_3)_2$ and $200 \ mL$ of $\frac{M}{10} \ KNO_3$ solutions are mixed. What is the normality of the resulting solution with respect to $NO_3^{-}$ ions (in $N$)?