A chemist has found experimentally that a 0.01 $\frac{mol}{L}$ chloric acid solution has an ionisation degree of 0.62. What is the value of $pK_a$ he deduces?
$HClO_2$: weak acid $K_a$ $=$ $\frac{\alpha^2c }{1-\alpha}$ = $\frac{0.62^20.01}{1-0.62}$ $pK_a$ $=$ $-log(\frac{0.62^20.01}{1-0.62})$ = 2
