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

Equal masses of ethane and hydrogen are mixed in an empty container at 298 K. The fraction of total pressure exerted by hydrogen is

K_f (water) = 1.86 K kg mol^-1. The temperature at which ice begins to separate from a mixture of 10 mass % ethylene glycol is

Equal weights of ethane and hydrogen are mixed in an empty container at 25$$^\circ$$C. The fraction of total pressure exerted by hydrogen is