Question

.
Calculate the depression in the freezing point of water when 10 g of
CH,CH,CHCICOOH is added to 250 g of water. K = 1.4 x 10", K = 1.86
K kg mol-'.​

Answer 1

Explanation:

The molar mass of 2-chloro butanoic acid is 122.5 g/mol. 

Number of moles =122.510=0.0816 mol

Molality of solution =2500.0816×1000=0.3265 m

Let α be the degree of dissociation and c be the initial concentration. The concentration after dissociation is as shown.

c(1−α)CH3CH2CHClCOOH⇌cαCH3CH2CHClCOO−+cαH+

The equilibrium constant expression is 

K=c(1−α)cα×cα=cα2

α=cK=0.32651.4×10−3=0.065

Calculation of vant Hoff factor:

(1−α)CH3CH2CHClCOOH⇌αCH3CH2CHClCOO−