Is it possible for acids to have a pH above 7? If so, under what circumstances would that be?
Answers
Answer:
Yes, you can have an acid whose pH is greater than 7.
Explanation:
Acidity is a measure of [H+] concentration in a solution. A convenient measurement is to use is the pH scale which makes the wide range of numbers involved easier to handle.
p H=- log [ H+ ]
This means that
[ H+]=10^-pH
Therefore solution of
[ H+]=10^-2 mol/l has a pH of 2.
A typical high school textbook will show a pH scale as going from 0 to 14.
A solution of pH 7 is said to be neutral. If the pH is less than 7 then the solution is acidic. If the pH is greater than 7 the solution is an alkali.
This works well under normal laboratory conditions but does not apply generally.
We need to consider the auto - ionisation of water.
Finally, an acidic solution is not necessarily where pH < 7, it is when,
{H+] (aq ) > {OH-} (aq)