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

Number of hydrogen ions present in $10$ millionth part of $1.33 \ cm^{3}$ of pure water at $25^{\circ} C$ is

Calculate $[H^{+}]$ concentration for solutions with $pH = 12.0$ and $pH = 5.6$.

The ionic product of water at $50^{\circ} C$ is $4 \times 10^{-14}$. The $pH$ and nature of water 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 with $pH$ less than $7$ is

The $pOH$ of beer is $10.0$. The hydrogen ion concentration will be