Question

If the elevation in boiling point of a solution of $10\, g$ of solute $(mol$. wt. $=100$) in $100\, g$ of water is $\Delta T_{b}$, the ebullioscopic constant of water is

• A. $10$
• B. $100 \, T_b$
• C. $\Delta \, T_b$
• D. $ \frac{\Delta \, T_b}{10} $

Answer 1

Answer: (C)

We know that, $\Delta T_{b} = \frac{1000 \times K_{b}\times W}{W\times M}$
$M = \frac{1000\times K_{b} \times W}{W \times \Delta T_{b}} $
$\Delta T_{b} = \frac{1000 \times K_{b}\times 10}{100\times 100}$
$\Delta T_{b} = K_{b}$