Solutions Question 9

Question 9 - 30 January - Shift 1

A solution containing $2 g$ of a non-volatile solute in $20 g$ of water boils at $373.52 K$. The molecular mass of the solute is $g mol^{-1}$. (Nearest integer)

Given, water boils at $373 K, K_b$ for water $=0.52 K kg mol^{-1}$

Show Answer

Answer: (100g)

Solution:

$\Delta T_b=373.52-373$

$=0.52$

$\Delta T_b=Kb \cdot m$

$0.52=0.52 \times \frac{2}{\text{ Molar Mass }} \times \frac{1}{20 \times 10^{-3}}$

Molar Mass $=100 g / mol$