Answer to Question #112018 in Physical Chemistry for DEEPAK SINGH

Question

19.5g CH3FCOOH is dissolved in 500g of water the depression in the freezing point observed is 1.0k calculate van't hoff factor and dissociation constant of the acid.

Answer 1

Solution.

$\Delta T = i \times K(cr) \times Cm$

$Cm = \frac{19.5}{78.04 \times 0.5} = 0.50 \ mol/kg$

$i = \frac{\Delta T}{K(cr) \times Cm} = 1.08$

$\alpha = \frac{i-1}{k-1} = 0.08$

$Ka = \frac{\alpha^2C}{1- \alpha}$

$Ka = 3.48 \times 10^{-3}$

Answer:

i = 1.08

$Ka = 3.48 \times 10^{-3}$