Calculate the $pH$ of $0.01 \ M$ strong dibasic acid.

Given below are two statements:
Statement-$I$: $pH$ of a $1.0 \times 10^{-8} \ M$ solution of $HCl$ is $8$ at $25^{\circ} C$.
Statement-$II$: $HCl$ is a strong acid and negative log of $H^{+}$ concentration is called $pH$.
In the light of the above statements,choose the most appropriate answer from the options given below:

$600 \, mL$ of $0.01 \, M \, HCl$ is mixed with $400 \, mL$ of $0.01 \, M \, H_2SO_4$. The $pH$ of the mixture is $....... \times 10^{-2}$. (Nearest integer) [Given $\log 2 = 0.30, \quad \log 3 = 0.48, \quad \log 5 = 0.69, \quad \log 7 = 0.84, \quad \log 11 = 1.04$]

How many litres of water must be added to $1 \ L$ of an aqueous solution of $HCl$ with a $pH$ of $1$ to create an aqueous solution with $pH$ of $2$?

Calculate the $pH$ of $0.0035 \ M \ Ba(OH)_2$ solution.

At $298 \, K$,what is the concentration of hydrogen ions in a $10^{-8} \, M \, HCl$ aqueous solution? $(K_W = 10^{-14})$