Which of the following solutions are isotonic with respect to one another?

(1) 0.15 M urea

(2) 0.05 M CaCl₂

(3) 0.1 M MgSO₄

(4) 0.15 M glucose

Select the correct answer using the codes given below:

1, 2 and 4

We know,

\(\pi = iCRT\)

\(\pi (\text{0.15 M urea} = 1 × 0.15RT = 0.15RT)\) -------(1)

\(\pi (\text{0.05 M }CaCl_2\text{ = }1 × 0.05RT = 0.15RT)\) -------(2)

\(\pi (\text{0.1 M } MgSO_4\text{ = }2 × 0.1RT = 0.2RT)\) -------(3)

\(\pi (\text{0.15 M glucose} = 1 × 0.15RT = 0.15RT)\) -------(4)

From equations (1), (2), (3), and (4), we can clearly see that equations (1), (2) and (4) are equal. Hence they are isotonic.