Which of the following has a $pH$ of $12$?

The $pH$ of a $0.02 \, M$ solution of hydrochloric acid is

When $10^{-8} \ mol$ of $HCl$ is dissolved in one litre of water,the $pH$ of the solution will be

If $0.561 \, g$ of $KOH$ is dissolved in water to give $200 \, mL$ of solution at $298 \, K$. Calculate the concentrations of potassium,hydrogen and hydroxyl ions. What is its $pH$?

Calculate the volume of $0.1 \ M \ NaOH$ required to complete the neutralization of $300 \ mL$ of $HCl$ solution having $pH = 2.25$. (in $mL$)

$50 \, mL$ water is added to a $50 \, mL$ solution of $Ba(OH)_2$ of strength $0.01 \, M$. The $pH$ value of the resulting solution will be