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 solutions have identical osmotic pressures ($\pi_1 = \pi_2$), meaning their effective concentrations ($i \times C$) are equal. $i \times 0.004 = 1 \times 0.010 \implies i = 2.5$. For $Na_2SO_4$, $n=3$ ions ($2 Na^+$ and $SO_4^{2-}$). Using $i = 1 + \alpha(n-1) \implies 2.5 = 1 + \alpha(3-1) \implies 2.5 = 1 + 2\alpha \implies \alpha = 0.75$ or $75\%$.