$K_{a}$ for butyric acid $(C_{3}H_{7}COOH)$ is $2 \times 10^{-5}$. The $pH$ of $0.2 \ M$ solution of butyric acid is $........... \times 10^{-1}$. (Nearest integer) [Given $\log 2 = 0.30$]

The first and second ionization constants of $H_2X$ are $2.5 \times 10^{-8}$ and $1.0 \times 10^{-13}$ respectively. The concentration of $X^{2-}$ in $0.1 \ M$ $H_2X$ solution is . . . . . . $\times 10^{-15} \ M$. The value of $Y$ is:

The $pH$ of $0.1 \, M$ acetic acid solution is closest to $.....$ [Dissociation constant of the acid,$K_{a} = 1.8 \times 10^{-5}$]

The $pH$ of $0.01 \ M \ BOH$ solution is $10$. What is its degree of dissociation (in $\%$)? (Given $K_{b}$ of $BOH$ is $1 \times 10^{-6}$)

Dimethyl amine $(CH_3)_2NH$ is a weak base and its ionization constant is $5.4 \times 10^{-5}$. Calculate $[OH^{-}]$,$[H_3O^{+}]$,$pOH$ and $pH$ of its $0.2 \ M$ solution at equilibrium.

It has been found that the $pH$ of a $0.01 \ M$ solution of an organic acid is $4.15$. Calculate the concentration of the anion,the ionization constant of the acid and its $pK_a$.