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

💡 Solution & Explanation

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