Question

1) In the determination of molar mass of A+ and B– using a colligative property, what may be the value of van’t Hoff factor if the solute is 50% dissociated?

 

Answer 1

Answer : i = 1.5

Explanation :

Reaction : 

AB   -------> A+  +    B-

Calculations :

Since, the dissociation of solution is 50 % .

Then, coefficient of dissociation is 0.5.

α = (i - 1)/(n - 1)

Where, i = Van't Hoff factor 

             n = no.of ions dissociated 

Here,  i = ?, n = 2, α = 0.5

0.5 = (i - 1)/(2 - 1)

    i = 1.5 

Thus, van't Hoff factor for given reaction is 1.5.

i = 1.5