Question

The elevation in boiling point of a solution of 10 g of a binary electrolyte, having molecular mass 100 $gmo{l}^{-1}$ in 100 g of water is $△T_b$. The, value of $K_b$ for water is:

• A. $\frac{△T_b}{2}$
• B. 10
• C. $10△T_b$
• D. $\frac{△T_b}{10}$

Answer 1

The correct option is A $\frac{△T_b}{2}$

We have,

$\Delta T_b=i{K}_{b}m$

For binary electrolyte $i=2$

$\Delta T_b=2K_b\times \frac{10}{100\times 100}\times 1000$

$\therefore$, $K_b=\frac{\Delta T_b}{2}$

Hence, option $\left(A\right)$ is correct.