Question

The $pH$ of $10M$ $HCl$ aqueous solution is:

• A. $0$
• B. $1$
• C. $2$
• D. $<0$

Answer 1

The correct option is D $<0$

$p_H$=$-lo{g}_{10}\left[H^{+}\right]$

$p_H=-1$

A $10MHCl$ solution will not be fully dissociated ($\alpha \ne 1)$. Therefore its PH will be less than zero but not -1.