Hydrolysis of Salts and pH of their Solutions

The degree of hydrolysis of  $0.1\mathrm{M}$ solution of conjugate base of $\mathrm{HA} \mathrm{is} 0.01$. Find the ${\mathrm{H}}^{+}$ concentration in $0.4\mathrm{M}$ solution of ${\mathrm{A}}^{-}$

The degree of hydrolysis of $0.1\mathrm{M}$ solution of ${{\mathrm{ArNH}}_3}^{+}{\mathrm{CI}}^{-} \mathrm{is} 0.01$. Find the  ${\mathrm{H}}^{+}$ concentration in $0.4\mathrm{M}$ solution of ${{\mathrm{ArNH}}_3}^{+}{\mathrm{CI}}^{-}$

The correct order for the increasing extent of hydrolysis is-

Which statement/ relationship is correct? 

The sodium salt of a certain weak monobasic organic acid is hydrolysed to an extent of $3\%$ in its $0.1 \mathrm{M}$ solution at $25°\mathrm{C}$. Given that the ionic product of water is ${10}^{-14}$ at this temperature, what is the dissociation constant of the acid?

A $2.5 \mathrm{g}$ impure sample containing weak monoacidic base (Mol. wt. $=45 \mathrm{u}$) is dissolved in $100 \mathrm{mL}$ water and titrated with $0.5 \mathrm{M}$ $\mathrm{HCI}$. When ${\left(\frac{1}{5}\right)}^{\text{th }}$ of the base was neutralised, the $\mathrm{pH}$ was found to be $9$ and at equivalence point, $\mathrm{pH}$ of solution is $4.5$. Select correct statement(s):

What will be the $\mathrm{pH}$at the equivalence point during the titration of a $100 \mathrm{mL}$ $0.2$$\mathrm{M}$ solution of ${\mathrm{CH}}_3\mathrm{COONa}$ with $0.2 \mathrm{M}$ solution of $\mathrm{HCl} ? {\mathrm{K}}_{\mathrm{a}}=2\times {10}^{-5}$?

The degree of hydrolysis of a salt of a weak acid and a weak base in its $0.1 \mathrm{M}$ solution is found to be $50\%$. If the molarity of the solution is $0.2 \mathrm{M}$, then the percentage hydrolysis of the salt should be

What is the percentage hydrolysis of $\mathrm{NaCN}$ in $\mathrm{N}/80$ solution when the dissociation constant for $\mathrm{HCN}$ is $1.3\times {10}^{-9}$ and ${\mathrm{K}}_{\mathrm{w}}=1.0\times {10}^{-14}$.