Colligative properties

The observed osmotic pressure for a 0.10 M solution of $\ce{Fe(NH4)2(SO4)2}$ at 25°C is 10.8 atm. The expected and experimental (observed) values of Van't Hoff factor (i) will be respectively :

(R = 0.082 L atm k$^{-1}$ mol$^{-1}$)

For a dilute solution containing 2.5 g of a non-volatile non-electrolyte solute in 100 g of water, the elevation in boiling point at 1 atm pressure is 2 °C. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure (mm of Hg) of the solution is (take $K_b=0.76$ K kg mol⁻¹)

The freezing point (in °C) of a solution containing 0.1 g of $\ce{K3[Fe(CN)6]}$ (Mol. Wt. 329) in 100 g of water ($K_f=1.86$ K kg mol$^{-1}$) is

The freezing point of the solution M is

Water is added to the solution M such that the mole fraction of water in the solution becomes 0.9. The boiling point of this solution is

When 20 g of naphthoic acid ($\ce{C11H8O2}$) is dissolved in 50 g of benzene ($K_f=1.72$ K kg mol⁻¹), a freezing point depression of 2 K is observed. The van't Hoff factor ($i$) is