# Does the presence of an acid in a water solution affect the pH of the solution?

Nov 20, 2017

My word.....

#### Explanation:

By definition, $p H \equiv \text{pouvoir hydrogene}$, i.e. $\text{power of hydrogen}$ is equal to $- {\log}_{10} \left[{H}_{3} {O}^{+}\right]$.

Strong acids gives low to negative $p H$ values, depending on the concentration of the acid, and the inherent acid strength. Weaker acids give $p H < 7$...

Strong acids protonate the water solvent and give solutions that are stoichiometric in ${H}_{3} {O}^{+}$...

$H C l \left(a q\right) + {H}_{2} O \left(l\right) \rightarrow {H}_{3} {O}^{+} + C {l}^{-}$

A weaker acid will not give such a precipitous drop in $p H$, however, the $p H$ will drop somewhat from $7$...the $p H$ of $1.0 \cdot m o l \cdot {L}^{-} 1$ acetic acid is $2.37$.........