Question

3 g of acetic acid is dissolved in 500 g of water. Depression in freezing point of solution is x × 10^-1K. Value of x to the nearest integer.

Given : K_a of CH₃COOH = 1.8 × 10^–5 and 

K_f of water = 1.86 K/molal 

Density of water = 1 g/mL

Answer 1

Correct answer is : 2

\(CH_3 COOH \rightleftharpoons CH_3 COO^- + H ^+\)

(Assuming \(\alpha\) << 1)

= 0.188 

= 1.88 x 10^-1 

x \(\simeq\) 2