You are told that the solutions in two beakers are both 0.02 M solutions of acids "A" is weak acid and acid "B" is a strong acid. Which of the two acids would have the lower pH, acid "A" or acid "B"? Explain your answer.

3 answers

strong acid have more H+ ions in solution.
strong acid has lower pH
Just to expand a little on bobpursley's answer, yes, acid A will have a lower a higher H+ ion concentration and thus a lower pH

BECAUSE

since you an equal amount of each solution (0.02 M), the solution that dissociates more will have a higher H+ concentration. The strong acid will dissociate 100%, while the weak acid will only partially dissociate. Thus, the strong acid in this case will have a lower pH.