pH of acids

[ng1D]

Why do solutions of weak acids have higher pH values than solutions of strong acids at the same concentration?

[Eesha Chattopadhyay 2K]

Strong acids have a higher percent ionization than weak acids, so there is more H30 present in solutions with strong acids, causing them to have a lower pH.

[Gabriella Bates 2L]

A strong acid has a tendancy to dissociate in water, and therefore will have a higher concentration of H+ ions and a lower pH. In contrast, a weak acid will not dissociate as much, and will therefore have a lower concentration of H+ ions and a higher pH.

[Owen-Koetters-4I]

Strong acids have higher percent ionization and as a result there is more h3o+ in solution, leading to a lower ph value

[Jiyoon_Hwang_2I]

Weak acids have higher pH because they’re essentially closer to 7 (neutral pH) and strong acids are on the farther side of the pH spectrum which is why they have a lower pH

[Sydney Pell 2E]

At the same concentration, weak acids will not dissociate as much as strong acids will. This means that weak acids have lower concentrations of H3O+ and therefore their pH will be closer to 7 while strong acids will have much lower pH because of their higher hydronium concentration.

[Veronica Lu 2H]

weak acids have a pH that's closer to 7 (neutral)

[Ayushi2011]

Strong acids dissociate completely, while weak acids don't which affects the ph.

[Tauhid Islam- 1H]

The stronger the acid, the lower the pH of the solution. You would expect weak acids to have higher pH values. Also pH is equal to -log concentration of H+ ions in the solutions. Because of partial disassociation of weak acids, you get less H+ ions meaning a higher pH in comparison to strong acids that completely disassociate.

[Charlene Datu 2E]

Weak acids are only partially ionized, in comparison to the strong acid that is completely ionized. With a lower concentration of [H+] in the solution, the weak acid would have a higher pH. Conversely, the strong acid would have a higher concentration of [H+] in the solution, resulting in a lower pH.

[BAlvarado_1L]

pH=-log[H+] and strong acids cause there to be a high [H+] than weak acids this strong acids have a pH closer to 0 while weak acids are closer to 7 on the scale of 0-7

[SVajragiri_1C]

Strong acids disassociate almost completely into hydronium ions, while weak acids only partially disassociate into hydronium ions. If the two acids are at the same concentration, the concentration of hydronium ions will be less for the weak acids. Since pH is the -log of the concentration of hydronium ions, the more hydronium ions there are, the lower the pH will be.

[Madeline Ogden 3B]

Since a higher pH signifies a more basic solution, weaker acids tend to have a higher pH than stronger ones. This is because pH refers to the content of hydronium (H30+) ions present in a solution. Weaker acids tend to not completely disassociate in water meaning that they'll have a higher content of H30+ ions and therefore a higher pH.

[Karl Yost 1L]

Recall: pH is the -log[H⁺].

The terms 'weak' and 'strong' are used to describe the extent that an acid/base dissociates in solution. Hydrochloric acid (HCl), for instance, is a strong acid, while ethanoic acid (CH3COOH) is a weak acid. Knowing this is important to answering your question, as a strong acid like HCl will completely dissociate in solution:

HCl (aq) --> Cl^- (aq) + H⁺ (aq)

This means that, relative to a weak acid (which will only partially dissociate), the concentration of H⁺ will be greater.

Since pH the -log[H⁺], a greater concentration of hydrogen ions corresponds to a lower pH — and vice versa.