Question

75.2 g of phenol is dissolved in 1 kg of solvent of kf=14 if the depresssion in frezeng point is 7k then find the %phenol that demerises

Answer 1

Mb =  

Taking the solvent as 1 kg

Mb =  

= 150.4 g per mol

phenol (molar mass) — 94 g/mol

i =  

i = 94 / 150.4 = 0.625

 

We have, 2C6H5OH ↔ (C6H5OH)2

1 0

1- α α/2

Total = 1- α + α/2

i = 1- α/2

0.625 = 1- α/2

α/2 = 0.375

α = 0.375/2

α = 0.75

% of phenol that dimerizes = 75%