Write characteristics and uses of ${K_a}$ value.

The characteristics and uses of $\mathrm{K}_{a}$ value as under :

$(i)$ The value of $\mathrm{K}_{a}$ is larger, the stronger is the acid.

$(ii)$ $\mathrm{K}_{a}$ is a dimensionless quantity.

$(iii)$ $\left[\mathrm{H}^{+}\right]$of weak acid and $\mathrm{pH}$ calculate using of value of $\mathrm{K}_{a}$.

$(iv)$ Calculate the ionization degree $\alpha$ with the help of $K_{a}$ value.

$(v)$ $\mathrm{pK}_{a}$ is calculated by using the value of $\mathrm{K}_{a}$. $\mathrm{pK}_{a}=-\log \left(\mathrm{K}_{a}\right)$

If the $\mathrm{pK}_{a}$ value is more than the acid become less strong.

$\mathrm{K}_{a}=1 \times 10^{-1}$	$1 \times 10^{-2}$	$1 \times 10^{-3}$
$\mathrm{pK}_{a}=1$	$2$	$3$