Question

A solution containing 1.23 g of $Ca(N{O}_3{)}_2$ in 10 g of water boils at $100-{97}^{o}C$. Calculate degree of ionisation of the nitrate ($K_b=0\cdot 52$).

Answer 1

Given - 1.23 g of $Ca(N{O}_3{)}_2$ in 10 g of $H_{2}O$. $K_b=0.52$

We know that, $K_b=C{\alpha }^2$

$\alpha$ - Degree of Dissociation C - Molarity / Molality

C = $\frac{1.24}{164}\times \frac{1000}{10}$ = 0.75

$K_b=C{\alpha }^2\Rightarrow \alpha =\sqrt{\frac{K_b}{C}}=\sqrt{\frac{0.52}{0.75}}=\sqrt{0.69}=0.83$

Hence the degree of dissociation is 0.83 .