Which of the following solutions has the highest $pH = 14$?

Calculate the $pH$ of $0.01 \ M$ strong dibasic acid.

The $pH$ of $10^{-7} \, M \, HCl$ is ......

The $pH$ of a solution produced when an aqueous solution of $pH$ $6$ is mixed with an equal volume of an aqueous solution of $pH$ $3$ is about:

Equal volumes of two solutions $A$ and $B$ of a strong acid having $pH=6.0$ and $pH=4.0$ respectively are mixed together to form a new solution. The $pH$ of the new solution will be in the range

$1.825 \ g$ of $HCl$ is dissolved in $5 \ L$ of water. What are the concentrations of $H^+$ and $OH^-$ ions?