When $NaCl$ is dissolved in water,the sodium ion undergoes ......... .

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

The ionic product of water is equal to .......

Statement-$I$ :- $pH$ of pure water increases with increase in temperature.
Statement-$II$ :- Degree of ionisation increases with increase in temperature.

The $pH$ in the stomach is approximately:

For the following Assertion and Reason,the correct option is
Assertion : The $pH$ of water increases with increase in temperature.
Reason : The dissociation of water into $H^{+}$ and $OH^{-}$ is an exothermic reaction.