During the titration of acetic acid with an aqueous $NaOH$ solution,the neutralization graph shows a vertical line. This line indicates:

$5 \ mL$ of $0.4 \ N$ $NaOH$ is mixed with $20 \ mL$ of $0.1 \ N$ $HCl$. The $pH$ of the resulting solution will be

$A$ weak acid is titrated with a weak base. Consider the following statements regarding the $pH$ of the solution at the equivalence point.
$(i)$ $pH$ depends on the concentration of acid and base
$(ii)$ $pH$ is independent of the concentration of acid and base
$(iii)$ $pH$ depends on the $pK_{a}$ of acid and $pK_{b}$ of base
$(iv)$ $pH$ is independent of the $pK_{a}$ of acid and $pK_{b}$ of base
The correct statements are

How much heat will be evolved when $500 \, mL$ of $0.2 \, N \, H_2SO_4$ is mixed with $50 \, mL$ of $1 \, N \, KOH$?

Which $pH$ value is higher in the following pairs?
$(a)$ $0.1 \ M \ HCl$ and $0.1 \ M \ NaOH$
$(b)$ $0.1 \ M \ HCl$ and $0.01 \ M \ HCl$
$(c)$ $0.1 \ M \ NaOH$ and $0.01 \ M \ NaOH$

The $pH$ at which the maximum hydrate is present in a solution of oxaloacetic acid $(HOOC-CO-CH_2-COOH)$ with $pK_{a1} = 2.2$ and $pK_{a2} = 3.98$ is: