Question

What is the hydronium concentration of an HCl solution with a pH of 3.0?

Answer 1

HCl is a strong acid, so in solution, it will release all the H+ ions that are in the molecule. Therefore, the concentration of HCl acid will be equal to the concentration of H+ ions.

The concentration of H+ ions can be found by means of the pH equation that says:

`pH=-log\lbrack H^+\rbrack`

where [H+] is the concentration (Molarity) of H+ ions (Hydronium).

By clearing the concentration of H+ we have:

`\lbrack H^+\rbrack=10^(-pH)`

We replace the value of pH into the equation:

`\lbrack H^+\rbrack=10^(-3)M=0.001M`

Answer: the hydronium concentration of an HCl solution with a pH of 3.0 is 0.001M