The highest $pH$ $(14)$ will be of which of the following?

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 $pH$?

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

$50 \ mL$ water is mixed with $50 \ mL$ $0.01 \ M$ $Ba(OH)_2$. Calculate its $pH$.

Which will have maximum $pH$?

$0.023 \ g$ of sodium metal is reacted with $100 \ cm^{3}$ of water. The $pH$ of the resulting solution is