At $300 \mathrm{~K}, 0.06 \mathrm{~kg}$ of an organic solute is dissolved in 1 kg water. The vapour pressure of solution at 300 K is 3.768 kPa . If vapour pressure of water at that temperature is 3.78 kPa , what is the molar mass of the organic solute (in $\mathrm{g} \mathrm{mol}^{-1}$ )? Assume the solution is dilute

Dry air contains $79 \% \mathrm{~N}_2$ and $21 \% \mathrm{O}_2$. At $T(\mathrm{~K})$, if Henry's law constants for $\mathrm{N}_2$ and $\mathrm{O}_2$ in water are $857 \times 10^4 \mathrm{~atm}$ and $4.56 \times 10^4 \mathrm{~atm}$, the ratio of mole fraction of $\mathrm{N}_2$ and $\mathrm{O}_2$ dissolved in water at 1 atm is

Distilled water boils at 373.15 K and freezes at 273.15 K . A solution of glucose in distilled water boils at 373.202 K . What is the freezing point (in K ) of the same solution? (For water, $K_b=0.52 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$, $K_f=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$ )

An aqueous solution of a non-volatile solute boils at $100.17^{\circ} \mathrm{C}$. The temperature at which this solution will freeze (in ${ }^{\circ} \mathrm{C}$ ) is

$$ \begin{aligned} & \left(K_b\left(\mathrm{H}_2 \mathrm{O}\right)=0.512^{\circ} \mathrm{C} \mathrm{~kg} \mathrm{~mol}^{-1},\right. \\ & \left.K_f\left(\mathrm{H}_2 \mathrm{O}\right)=1.86^{\circ} \mathrm{C} \mathrm{~kg} \mathrm{~mol}^{-1}\right) \end{aligned} $$