What is the concentration of hydronium ions in a solution that has a pH of -3? Why is such a solution impossible to prepare?

1 Answer
Jan 3, 2017

Answer:

Both of these questions can be answered by one calculation - the #["H"_3"O"^+]# for this pH.

Explanation:

Negative pH values correspond to very high levels of #"H"_3"O"^+# concentration.

Mathematically, the relation is

#["H"_3"O"^+]=10^(-"pH")#

If the pH is negative, the expression becomes

#["H"_3"O"^+]=10^(-(-3))= 10^3="1000 mol/L"#

In answer to your second question, it is not possible to add sufficient solute to a solution to reach a concentration of #"1000 mol/L"#! Even in the case of a low-mass strong acid like #"HCl"#, this would require #"36500 g"# dissolved in only one litre of solution!