Question

A solution of 1.25 g of non electrolyte in 20 g Of water frwezes at 271.94 k. If kf is 1.86 then mol weight of solute

Answer 1

here's your answer........


I hope you understand my answer.....

Answer 2

Answer; Molar weight of electrolyte is 96.07 g/mol

Explanation:

Depression in freezing point :

Formula used for lowering in freezing point is,

$\Delta T_f=K_f\times m=K_f\times \frac{\text{ given weight of electrolyte}}{\text{Molar weight of electrolyte}\times \text{ Mass of solvent of kg}}$

where,

$T_f$ = change in freezing point

$k_f$ = freezing point constant

m = molality

$Delta T_f=T_o-T_f=273.15 K-271.94 K=1.21 K$

$\Delta T_f=1.21 K=1.86\times \frac{1.25 g}{\text{Molar weight of electrolyte}\times 0.020 kg}$

Molar weight of electrolyte = 96.07 g/mol