pH of weak acids vs strong acids

[Adelyne_Tran_1J]

Why do solutions with weak acids have a higher pH than solutions with strong acids at the same concentration. I understand that it has to do with the amount of H+ ions released in solution, but I'm not sure what the entire reasoning is.

[Andy Sun 2I]

Weak acids do not completely dissociate into ions whereas strong acids do. Therefore, if you start with the same concentration of acid, the strong acid will create a higher H+ concentration, which leads to a lower pH, whereas the weak acid will not produce as much H+, leading to a pH that is not as low as it would if the acid was strong.

[Vishwa Diwan 1D]

pH is actually kind of a backwards scale due to the logarithm used to calculate the pH using the hydronium concentration. So that's why a lower pH actually has a higher concentration of H+ due to the way the logarithm is set up to solve for it and thus the higher the pH the lower the concentration.

[Jane_S 2C]

I think of it as a backwards scale. Strong acids dissociate fully, which means they release more H+ ions, leading to a lower pH.

[Isabelle Kim 3E]

A weaker acid does not fully dissociate like how a stronger acid would, which also indicates that a weaker acid forms way less H3O+ ions in the aqueous solution. With less H3O+ ions, the solution of a weaker acid would have a pH level that is lower than that of a stronger acid.

[505801516]

since strong acids will fully dissociate, they release more ions of H+. when more H+ ions are released, this gives you a lower pH value.

[Kathleen Vo 1G]

Generally, the stronger the acid, the lower the pH. For example HCl, is a common strong acid, with its pH being close to 0-1 due to the high concentration of hydrogen ions in the solution. Vice versa, the weaker the acid, the higher the pH.

Additionally, when referring to strength of an acid, the stronger the acid, the lower the pKa due to its higher ability to transfer protons.

Stronger acid = lower pH, lower pKa

[Elise Van Meter 2H]

Hi! The principal difference between strong acids and weak acids is that while strong acids fully dissociate in solution, weak acids do not. As a result, the Ka value of strong acids is higher than that of weak acids, and, accordingly, the pKa value of strong acids is less than that of weak acids. As the dissociation of strong acids leads to the release of more H+ ions into solution, the resulting solution is more acidic, and, as pH is measured on a logarithmic scale, a higher value of H+ ions equates to a lower value of pH. Therefore, as weak acids release fewer H+ ions into solution, the resulting solution is less acidic and the pH value is higher. I hope this is helpful!

[kayla fullerton 3A]

Since strong acids fully dissociate, the concentration of H+ ions is assumed to be the same as was in the strong acid. When calculating [H30+] in weak acids, you would use the ICE table and subtract x from the initial acid concentration.

[Arambula 1H]

pH is inversely related to the strength of the acid. So a weaker acid has a higher pH because it can't disociate fully and release as many H+ ions as a strong acid which can disociate fully. This allows strong acids to record a lower pH since it measures this [H3O+] that forms using these hydrogen ions.