$0.1 \ (M) \ HCl$ and $0.1 \ (M) \ H_2SO_4$ each of volume $2 \ mL$ are mixed and the volume is made up to $6 \ mL$ by adding $2 \ mL$ of $0.01 \ (N) \ NaCl$ solution. The $pH$ of the resulting mixture is

The $pH$ of $10^{-8} \ M \ HCl$ solution is

What will be the concentration of $H^{+}$ ions in a solution prepared by dissolving $4 \ g$ of $NaOH$ in $100 \ mL$ of water at $25 \ ^{\circ}C$?

Following solutions were prepared by mixing different volumes of $NaOH$ and $HCl$ of different concentrations:
$a. \; 60 \; mL \; \frac{M}{10} \; HCl + 40 \; mL \; \frac{M}{10} \; NaOH$
$b. \; 55 \; mL \; \frac{M}{10} \; HCl + 45 \; mL \; \frac{M}{10} \; NaOH$
$c. \; 75 \; mL \; \frac{M}{5} \; HCl + 25 \; mL \; \frac{M}{5} \; NaOH$
$d. \; 100 \; mL \; \frac{M}{10} \; HCl + 100 \; mL \; \frac{M}{10} \; NaOH$
$pH$ of which one of them will be equal to $1$?

$75 \ mL$ of $0.2 \ M \ HCl$ is mixed with $25 \ mL$ of $1 \ M \ HCl$. To this solution, $300 \ mL$ of distilled water is added. What is the $pH$ of the resultant solution?

The $pH$ of a solution obtained by mixing $50 \ mL$ of $0.4 \ N \ HCl$ and $50 \ mL$ of $0.2 \ N \ NaOH$ is