A solution of is observed to be exactly isotonic with a aqueous solution of glucose at the same temp — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Isotonic means equal effective concentrations: $i_1 C_1 = i_2 C_2$. For $Na_2SO_4$, $i \times 0.004 = 1 \times 0.010 \implies i = 2.5$. The salt yields $n=3$ ions. Using $i = 1 + \alpha(n-1)$, we get $2.5 = 1 + 2\alpha \implies 1.5 = 2\alpha \implies \alpha = 0.75$ or $75\%$.