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.
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.
To determine which acid, either "A" or "B," has a lower pH, we need to understand pH and how it is affected by the strength of an acid.
The pH scale is a measure of the acidity or alkalinity of a solution. It ranges from 0 to 14, with a pH of 7 considered neutral. Values below 7 are acidic, while values above 7 are alkaline or basic. The lower the pH value, the higher the concentration of hydrogen ions (H+) in the solution, indicating stronger acidity.
Now you mentioned that acid "A" is a weak acid, while acid "B" is a strong acid. The term "weak" or "strong" refers to the degree of ionization or dissociation of an acid in water. Strong acids ionize almost entirely in water, producing a large concentration of hydrogen ions, while weak acids only partially ionize, resulting in a smaller concentration of hydrogen ions.
Given that both solutions are 0.02 M, we can infer that the concentration of acid "B" is fully dissociated since it is a strong acid. Consequently, it will have a higher concentration of hydrogen ions and therefore a lower pH value.
On the other hand, acid "A" being a weak acid, only partially ionizes, resulting in a lower concentration of hydrogen ions compared to acid "B." Therefore, acid "A" will have a higher pH value compared to acid "B."
In conclusion, acid "B" would have the lower pH since it is a strong acid, and strong acids fully ionize in solution, leading to a higher concentration of hydrogen ions.