The $pH$ of $1 \ N$ $KOH$ solution is:

What is the $pH$ of $10^{-9} \ M$ aqueous $HCl$ solution?

The $pH$ of $0.0001 \ N$ solution of $KOH$ will be

What will be the $pH$ of a solution formed by mixing $40 \, mL$ of $0.10 \, M \, HCl$ with $10 \, mL$ of $0.45 \, M \, NaOH$?

$0.1 \ (M) \ HCl$ 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

At $27^{\circ} C$, $100 \ mL$ of $0.5 \ M$ $HCl$ is mixed with $100 \ mL$ of $0.4 \ M$ $NaOH$ solution. To this resultant solution, $800 \ mL$ of distilled water is added. What is the $pH$ of the final solution?