What is the $pH$ of $0.005 \ M \ H_2SO_4$ solution?

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 $pH$?

$0.837 \ g$ of $Ba(OH)_2$ is dissolved in $100 \ mL$ of solution. Calculate the $pH$ of the solution. (Atomic masses: $Ba = 137, O = 16, H = 1$)

$0.001 \ mol$ of a strong electrolyte $M(OH)_2$ is dissolved to make $20 \ mL$ of a saturated solution. Calculate its $pH$ $(K_w = 1 \times 10^{-14})$.

Equal volumes of two solutions $A$ and $B$ of a strong acid having $pH=6.0$ and $pH=4.0$ respectively are mixed together to form a new solution. The $pH$ of the new solution will be in the range

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