When 0.004MNa2SO4 is isotonic with 0.01M solution of glucose at same temperature.the apparent degree of dissociation of sodium sulphate is
75%
For Na2SO4,π1=iMRT
=i×0.004×RT
For glucose, π2=CRT
= 0.01 RT
π1=π2 (isotonic)
or 0.004i = 0.01
i = 2.5
Na2SO4⇌1Na⊕+SO2−41001−α2αα
Total particles=1−α+2α+α
=1+2α∴i=1+2α1=2.5
α=0.75 or 75% dissociated