JEE PYQ: Solutions And Colligative Properties Question 1
Question 1 - 2021 (16 Mar Shift 1)
$\text{AB}_2$ is 10% dissociated in water to $\text{A}^{2+}$ and $\text{B}^-$. The boiling point of a 10.0 molal aqueous solution of $\text{AB}_2$ is ____ °C. (Round off to the Nearest Integer).
[Given: Molal elevation constant of water $K_b = 0.5$ K kg mol$^{-1}$, boiling point of pure water $= 100°C$]
Show Answer
Answer: 106
Solution
$\text{AB}_2 \rightarrow \text{A}^{2+} + 2\text{B}^-$. $i = 1 + 2\alpha = 1.2$. $\Delta T_b = i \times m \times K_b = 1.2 \times 10 \times 0.5 = 6$. Boiling point $= 106°C$.
BETA
