pH of acids

Moderators: Chem_Mod, Chem_Admin

ng1D
Posts: 43
Joined: Wed Sep 18, 2019 12:17 am

pH of acids

Postby ng1D » Sun Mar 15, 2020 7:51 am

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

Eesha Chattopadhyay 2K
Posts: 104
Joined: Fri Aug 09, 2019 12:16 am

Re: pH of acids

Postby Eesha Chattopadhyay 2K » Sun Mar 15, 2020 7:54 am

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
Posts: 113
Joined: Thu Jul 11, 2019 12:15 am

Re: pH of acids

Postby Gabriella Bates 2L » Sun Mar 15, 2020 7:56 am

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
Posts: 50
Joined: Fri Sep 28, 2018 12:16 am

Re: pH of acids

Postby Owen-Koetters-4I » Sun Mar 15, 2020 1:07 pm

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
Posts: 101
Joined: Sat Sep 14, 2019 12:17 am

Re: pH of acids

Postby Jiyoon_Hwang_2I » Sun Mar 15, 2020 1:17 pm

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
Posts: 100
Joined: Wed Sep 11, 2019 12:17 am

Re: pH of acids

Postby Sydney Pell 2E » Sun Mar 15, 2020 2:11 pm

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
Posts: 89
Joined: Wed Sep 18, 2019 12:18 am
Been upvoted: 1 time

Re: pH of acids

Postby Veronica Lu 2H » Sun Mar 15, 2020 3:02 pm

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

Ayushi2011
Posts: 101
Joined: Wed Feb 27, 2019 12:17 am

Re: pH of acids

Postby Ayushi2011 » Mon Mar 16, 2020 6:07 pm

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

Tauhid Islam- 1H
Posts: 64
Joined: Fri Aug 02, 2019 12:15 am

Re: pH of acids

Postby Tauhid Islam- 1H » Mon Mar 16, 2020 6:17 pm

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
Posts: 62
Joined: Wed Sep 11, 2019 12:16 am

Re: pH of acids

Postby Charlene Datu 2E » Mon Mar 16, 2020 7:20 pm

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
Posts: 49
Joined: Thu Jul 25, 2019 12:16 am

Re: pH of acids

Postby BAlvarado_1L » Tue Mar 17, 2020 12:32 pm

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
Posts: 115
Joined: Thu Jul 11, 2019 12:16 am

Re: pH of acids

Postby SVajragiri_1C » Tue Mar 17, 2020 8:38 pm

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.


Return to “Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions”

Who is online

Users browsing this forum: No registered users and 1 guest