At same temperature, which pair of the following solutions are isotonic solutions?

Options

A. `0.2M BaCI_(2)` and `0.2` urea
B. `0.1M` urea and `0.1M NaCI`
C. `0.1M NaCI` and `0.1M K_(2)SO_(4)`
D. `0.1M Ba (NO_(3))_(2)` and `0.1M Na_(2)SO_(4)`.

Answer

D

Explanation

Two solutions are isotonic if they have same molar concentrations of particles in solution.
`0.1 M Ba(NO_(3))_(2)=0.3 M` ion concentration
`0.1 M NaSO_(4) = 0.3 M` ion concentration