Would a solution of a weak acid (ethanoic acid) of identical concentration to HCL have the same pH?
The short answer is no. pH is a measure of the concentration of H+ ions in the solution, the more H+ ions the lower the pH (pH = -log [H]) H+ ions are released when an acid dissociates. HCl is a strong acid so a much greater proportion of it is dissociated than in a weak acid like ethanoic acid. This means that there are more free H+ ions in a solution of HCl than in a solution of the same concentration of a weak acid.