$0.01$ moles of a weak acid $HA \left( K _{ a }=2.0 \times 10^{-6}\right)$ is dissolved in $1.0\, L$ of $0.1\, M\, HCl$ solution. The degree of dissociation of $HA$ is …………. $\times 10^{-5}$

(Round off to the Nearest Integer).

[Neglect volume change on adding $HA$. Assume degree of dissociation $<< 1]$

The hydrogen ion concentration in weak acid of dissociation constant ${K_a}$ and concentration $c$ is nearly equal to

The $pH$ of $ 0.1 \,M$  solution of a weak monoprotic acid  $1\%$  ionized is

$K _{ a_1,}, K _{ a_2 }$ and $K _{ a_3}$ are the respective ionization constants for the following reactions $(a), (b),$ and $(c)$.

$(a)$ $H _{2} C _{2} O _{4} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{-}$

$(b)$ $HC _{2} O _{4}^{-} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{2-}$

$(c)$ $H _{2} C _{2} O _{4} \rightleftharpoons 2 H ^{+}+ C _{2} O _{4}^{2-}$

The relationship between $K_{a_{1}}, K_{ a _{2}}$ and $K_{ a _{3}}$ is given as