The correct option is C 0.15 M aqueous KHF2 solution showing complete dissociation
Given, molarity of NaCl solution (C)=0.2 M and
percentage of dissociation (α)=50%
For NaCl solution
πNaCl=i×CRT
i=1+(n−1)α
For NaCl, n=2i=1+(2−1)0.5=32
⇒πNaCl=32×0.2RT =0.3RT
(A) πGlucose=1×0.3×RT=0.3RT
(B) πNa2SO4=i×CRT
Now, iNa2SO4=1+(n−1)α=1+(3−1)
⇒πNa2SO4=3×0.15RT=0.45RT
(C) πKHF2=iCRT
iKHF2=1+(n−1)α
iKHF2=1+(2−1)1
⇒πKHF2=2×0.15RT=0.3RT
(D) πBaCl2=iCRT
iBaCl2=1+(n−1)α
=1+(3−1)0.8
⇒πBaCl2=2.6×0.1RT=0.26RT
Solutions having the same value of π are isotonic solution. Therefore, A and C are isotonic to given NaCl solution.