Question

75g of ethylene glycol is dissolved in 500g water. The solution is placed in a refrigerator maintained at a temperature of 263.7K. What amount of ice will separate out at this temperature.
(Kf water = 1.86 K/m

Answer 1

Answer:

258g

Explanation:

Depression in freezing point,

ΔTf = ΔTf ⁰ ( freezing point of pure solvent ) - Tf ( freezing point when non-volatile solute is dissolved in it)

      = 273 - 263.7 K= 9.3 K

Weight of the solvent ( water) W = (Kf * w * 1000) / m * ΔTf

Where,

m --  molar mass of the solute ( ethylene glycol )

w -- weight of the solute.

Kf ( given ) = 1.86 K/m

W = ( 1.86 * 75 *1000 ) / 62 * 9.3

   = 242g

Therefore, the amount of ice that  would be separated from 500g of water at this temperature would be 500 - 242 = 258 Grams.