What is the freezing point of 1 molal aqueous solution of a non volatile solute?

($$\mathrm{K}_{\mathrm{f}}=1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1})$$ ($$\mathrm{T}_{\mathrm{f}}^0$$ for water $$=0^{\circ} \mathrm{C})$$

Air is an example of a solution of

5 g sucrose (molar mass = 342) is dissolved in 100 g of solvent, decreases the freezing point by 2.15 K. What is cryoscopic constant of solvent?

What is Henry's law constant if solubility of a gas in water at $$298 \mathrm{~K}$$ and 1 bar pressure is $$7\times10^{-4} \mathrm{~mol} \mathrm{~L}^{-1}$$ ?