The $pH$ of a solution is the negative logarithm to the base $10$ of its hydrogen ion concentration in:

The concentration of hydrogen ion in a sample of soft drink is $3.8 \times 10^{-3} \ M$. What is its $pH$ (in $.42$)?

The $pH$ of rain water is approximately

At $25 \, ^\circ C$,the $pH$ value of a solution is $6$. The solution is:

The value of the ion product constant for water,$(K_w)$ at $60\,^{\circ}C$ is $9.6 \times 10^{-14} \,M^2$. What are the $[H_3O^{+}]$ of a neutral aqueous solution at $60\,^{\circ}C$ and the nature of an aqueous solution with a $pH = 7.0$ at $60\,^{\circ}C$,respectively?

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