Calculate the hydrogen ion concentration and the pH of each of the following solutions of strong acids.

Question

(a) 0.00010 M HCl

if you could just explain how to do this that would be great!

thanks

Answer 1

First you recognize that HCl is a strong acid and ionizes completely; therefore,
HCl + H2O ==> H3O^+ + Cl^-

So if you start with 0.00010 M HCl,knowing it is ionized completely, the H3O^+ must be 0.00010.
pH = -log(H^+) = -log(0.00010) = -(-4.0) = 4.0 and pH = 4.0