is supposed to be dissociated when a solution is prepared. Its boiling point is recorded to be equal — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

For $K_4[Fe(CN)_6]$, $n=5$. $i = 1 + 0.4(5-1) = 2.6$. Equal BP implies equal effective concentration: $i_1 C_1 = i_2 C_2$. $2.6 \times 1\text{ M} = 1 \times C_A$. $C_A = 2.6\text{ M}$. $20\% \text{ w/v} = 200\text{ g/L}$. $M_A = \frac{200}{2.6} = 76.92 \approx 77\text{ g mol}^{-1}$.