$K_a$ for $CH_3COOH$ is $1.9 \times 10^{-5}$. Calculate the $pH$ at the equivalence point in the titration of $0.1 \ M$ $CH_3COOH$ with $0.1 \ M$ $NaOH$.

The $pH$ of the solution containing $10 \ mL$ of $0.1 \ N$ $NaOH$ and $10 \ mL$ of $0.05 \ N$ $H_2SO_4$ would be

$5\%$ ionization occurs in $0.01 \ M$ $CH_3COOH$ solution. Calculate its dissociation constant.

What will be the change in acidity if
$(i)$ $CuSO_4$ is added in saturated $(NH_4)_2SO_4$ solution
$(ii)$ $SbF_5$ is added in anhydrous $HF$?

At $25^{\circ}C$,the dissociation constants of acetic acid and $HCN$ are $1.5 \times 10^{-5}$ and $4.5 \times 10^{-10}$ respectively. What is the equilibrium constant for the following reaction? $(CN^- + CH_3COOH \rightleftharpoons HCN + CH_3COO^-)$

Two solutions $A$ and $B$,each of $100 \; L$,were made by dissolving $4 \; g$ of $NaOH$ and $9.8 \; g$ of $H_{2}SO_{4}$ in water,respectively. The $pH$ of the resultant solution obtained by mixing $40 \; L$ of solution $A$ and $10 \; L$ of solution $B$ is: