At 300 K, 0.3 M sucrose solution is isotonic with 0.15 M KCl solution. Degree of dissociation of KCl in the solution is
For isotonic solution
i1M1sucrose=i2M2KCl 10.3M=i20.15M i2KCl=0.30.15=2 KCl1-α⇋K+α+Cl-α i = 1-α+α+α=1+α 1+α=2 α=2-1 α=1;