Question

The $pH$ of a $1\times {10}^{-8}M$ aqueous solution of $HCl$ is slightly less then $7$ because:

• A. the ionization of $HCl$ is incomplete
• B. the ionization of water is negligible
• C. the ionization of water at such a low concentration of $HCl$ is significant
• D. the ionization of both $HCl$ and water are negligible

Answer 1

The correct option is C the ionization of water at such a low concentration of $HCl$ is significant

The $pH$ of $1\times {10}^{-8}$M solution should be $8$ but it is slightly less than $7$ because of the ionization of water.

Water on dissociation gives an equal amount of $H^{+}$ and $O{H}^{-}$ ion.