Strong and Weak Acids

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Gillian Ward 1F
Posts: 61
Joined: Fri Sep 28, 2018 12:27 am

Strong and Weak Acids

Postby Gillian Ward 1F » Mon Jan 21, 2019 4:24 pm

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

Kessandra Ng 1K
Posts: 67
Joined: Fri Sep 28, 2018 12:25 am

Re: Strong and Weak Acids

Postby Kessandra Ng 1K » Mon Jan 21, 2019 4:31 pm

Weak acids don't fully dissociate in solution, so there is a lower concentration of H+ ion in solution. However for strong acids that fully dissociate, there are more H+ ions in solution which makes the solution more acidic and hence, have a lower pH value as compared to weak acids.

Anita Wong 1H
Posts: 68
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 2 times

Re: Strong and Weak Acids

Postby Anita Wong 1H » Mon Jan 21, 2019 4:31 pm

At equal concentrations, a strong acid will typically have a lower pH than a weak acid, since the strong one will donate more protons to the solution.

Luc Lorain 1L
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: Strong and Weak Acids

Postby Luc Lorain 1L » Mon Jan 21, 2019 4:35 pm

Remember that the pH scale is logarithmic and starts at 0, with the pH getting more acidic the closer to 0 one gets from 7 and more basic the farther from 7 one goes in the opposite direction. A weak acid will not dissociate as willingly as a strong acid (which are often very ionic in composition, such as HCl or HI), meaning that there will simply be fewer reactions resulting in [H3O+ formation when compared to a strong acid.


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