Question

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

• A. 0.2 M $BaCl_2$ and 0.2 urea
• B. 0.1 M urea and 0.1 M NaCl
• C. 0.1 M NaCl and 0.1 M $K_2S0_4$
• D. 0.1 M $Ba(N0_3)_2$ and $0.1 M Na_2SO_4$

Answer 1

Answer: (D)

0.1 M $Ba(N0_3)_2$ and $0.1 M Na_2SO_4$

Answer 2

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 $Na_2SO_4$ = 0.3 M ion concentration