At $90\,^{\circ}C$ pure water has $[H_3O^{+}] = 10^{-6}\,M$. The value of $K_w$ at this temperature will be:

At $25^{\circ}C$,if the concentration of $[OH^{-}]$ is $10^{-9} \ M$,find the $pOH$ value of the solution.

There are two different solutions, $A$ and $B$. The $pH$ of solution $A$ is $4$. Find the $pH$ of solution $B$ having $[H^+]$ concentration three times that of solution $A$.

On adding which of the following,the $pH$ of $20 \ mL$ of $0.1 \ N \ HCl$ will not alter?

If the value of the dissociation constant of water is $1.8 \times 10^{-16}$,what is the ionic product of water?

The $pH$ of a solution is $9.5$. The solution is