Which oxychloride has maximum $pH$

The $pH$ of $0.1\, M$ monobasic acid is $4.50$ Calculate the concentration of species $H ^{+},$ $A^{-}$ and $HA$ at equilibrium. Also, determine the value of $K_{a}$ and $pK _{a}$ of the monobasic acid.

If the dissociation constant of an acid $HA$ is $1 \times {10^{ - 5}},$ the $pH$ of a $ 0.1$  molar solution of the acid will be approximately

The solubility of a salt of weak acid $( A B )$ at $pH 3$ is $Y \times 10^{-3} mol L ^{-1}$. The value of $Y$ is

. . . . . (Given that the value of solubility product of $A B \left( K _{ sp }\right)=2 \times 10^{-10}$ and the value of ionization constant of $H B \left( K _{ a }\right)=1 \times 10^{-8}$ )

The ionization constant of dimethylamine is $5.4 \times 10^{-4}$. Calculate its degree of ionization in its $0.02$ $M$ solution. What percentage of dimethylamine is ionized if the solution is also $0.1 \,M$ in $NaOH ?$

At $298\,K$  a $0.1 \,M $ $C{H_3}COOH$ solution is $ 1.34\%$  ionized. The ionization constant ${K_a}$ for acetic acid will be