Calculate the solubility of gas in solvent at $25^{\circ} \mathrm{C}$ and 0.8 atm if Henry's law constant for solvent is $6.8 \times 10^{-4} \mathrm{~mol} \mathrm{dm}^{-3} \mathrm{~atm}^{-1}$.

Calculate osmotic pressure of 0.1 M aqueous solution of an electrolyte at 300 K if van't Hoff factor is 1.125. $\left[\mathrm{R}=0.0821 \mathrm{~atm} \mathrm{dm}^3 \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right]$