$1 \ L$ of $0.02 \ M$ aqueous $HCl$ is mixed with $1 \ L$ of $0.01 \ M$ aqueous $H_2SO_4$ solution. Assuming complete dissociation and no change in the volume upon mixing,the $pH$ of the resultant solution is $(\log_{10} 2 = 0.3)$.

What is the $pH$ of a solution containing $H^{+}$ ion concentration $2.5 \times 10^{-3} \ mol \ dm^{-3}$? (Given $\log 2.5 = 0.3979$)

Which of the following solutions will have the maximum $pH$?

$x \ mg$ of $Mg(OH)_2$ (molar mass $= 58 \ g/mol$) is required to be dissolved in $1.0 \ L$ of water to produce a $pH$ of $10.0$ at $298 \ K$. The value of $x$ is $........... mg$ ($Nearest$ $integer$). ($Given$: $Mg(OH)_2$ is assumed to dissociate completely in $H_2O$)

The hydrogen ion concentration of a $10^{-8} \ M \ HCl$ aqueous solution at $298 \ K$ $(K_w = 10^{-14})$ is

What is the $pH$ of a $0.005 \ M$ $Ba(OH)_2$ solution?