Solutions

If α is the degree of dissociation of Na2SO4, the vant Hoff’s factor (i) used for calculating the molecular mass is

  1. 1 + 2α
  2. 1 - α
  3. 1 + α
  4. 1 - 2α

Answer

Na2SO4 ↔ 2Na+ + SO42–

1               0          0

1 – α         2α        α

Vant Hoff factor (i) = (1 – α + 2α + α)/1

= 1 + 2α

The correct option is A.