The $[OH^{-}]$ in a solution is $1 \times 10^{-12} \ mol \ dm^{-3}$. What is the concentration of $H^{+}$ ions?

If a solution has $pOH$ value $12$ at $25\,^{\circ}C$,$H^{+}$ concentration should be

When the $pH$ of a solution is $2$,the hydrogen ion concentration in moles per litre is

Observe the following solutions:
$I$. Black coffee
$II$. $0.2 \ M \ NaOH$
$III$. Lemon juice
$IV$. Lime water
$V$. Human saliva
$VI$. Tomato juice
The number of solutions having $pH$ range of $1-7$ and $7-14$,in the above list,is respectively.

What is the $pH$ of a neutral solution at the normal temperature of the human body $(37^{\circ}C)$?

If the $pH$ of a solution is $2$,find the $[H^{+}]$ of the solution.