Question

Pure water freezes at 273 K and 1 bar. The addition of 34.5 g of ethanol to 500 g of water changes the
freezing point of the solution. Use the freezing point depression constant of water as 2 K kg mol⁻¹. The
figures shown below represent plots of vapour pressure (V.P.) versus temperature (T). [molecular weight of
ethanol is 46 g mol⁻¹]
Among the following, the option representing change the freezing point is

Answer 1

Answer:

The number of moles of ethanol n = 34.5 g46 g/mol = 0.75 mol .Molality m = 0.75 mol0.5 kg = 1.5 m The depression in freezing point Δ Tf = Kf m = 2 K .........