The initial rate of hydrolysis of methyl acetate $(1 \ M)$ by a weak acid $(HA, 1 \ M)$ is $1/100$th of that of a strong acid $(HX, 1 \ M)$ at $25^{\circ} C$. The $K_a$ of $HA$ is:

Which of the following statement$(s)$ is/are correct.
$A$. The $pH$ of $1 \times 10^{-8} \ M$ aqueous solution of $HCl$ is $8$
$B$. The conjugate base of $H_2PO_4^{\ominus}$ is $HPO_4^{2-}$
$C$. $K_w$ increases with increase in temperature
$D$. When a solution of a weak monoprotic acid is titrated against a strong base,then at the half-neutralization point,$pH = pK_a$.

The dissociation constant of acetic acid is $1.6 \times 10^{-5}$ and $\Lambda _{CH_3COOH}^o = 370.6 \times 10^{-4} \, S \, m^2 \, mol^{-1}$. The specific conductance of $0.01 \, M$ acetic acid solution will be approximately:

What is the concentration of $[OH^-]$ in a mixture of $20 \ mL$ of $0.050 \ M \ HCl$ and $30 \ mL$ of $0.10 \ M \ Ba(OH)_2$ (in $M$)?

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

The $pH$ value of a decinormal solution of $NH_4OH$ which is $20\%$ ionised,is