Question

Calculate the depression in the freezing point of water when 10 g of CH₃CH₂ CHCICOOH is added to 250 g of water. K_a = 1.4 × 10^-3 , K_f = 1.86 K kg mol^-1.

Answer 1

Molar mass of CH₃CH₂CHCICOOH = 15 + 14 + 13 + 35.5 + 45 = 122.5 g mol^-1 

If α is the degree of dissociation of CH₃CH₂CHCICOOH, then CH₃CH₂CHClCOOH  CH₃CHXHCICOO^- + H⁺

To calculate vant’s Hoff factor: CH₃CH₂CHCICOOH CH₃CH₂HCICOO^- + H⁺