pH values of weak and strong acids

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

pH values of weak and strong acids

Postby ng1D » Fri Jan 17, 2020 8:49 pm

Can someone explain why solutions of weak acids have higher pH values than solutions of strong acids at the
same concentration?

Samuel G Rivera - Discussion 4I
Posts: 61
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

Re: pH values of weak and strong acids

Postby Samuel G Rivera - Discussion 4I » Fri Jan 17, 2020 9:16 pm

A higher pH means a lower concentration of Hydrogen ions (protons). To go from pH to [H3O+], you calculate 10^(-pH). Therefore the higher the pH value, the lower the concentration of [H3O+] and the lower the acidity.

I'm not sure if this answers what you were asking, but I hope it helps.

Chantel_2I
Posts: 109
Joined: Sat Sep 07, 2019 12:19 am

Re: pH values of weak and strong acids

Postby Chantel_2I » Sat Jan 18, 2020 3:52 pm

Because weak acids do not dissociate completely, some concentration of a weak acid would produce less H3O+ than the same concentration of a strong acid. Therefore, the concentration of H3O+ will be lower with the weak acid, so the pH will be higher.

Karina Kong 2H
Posts: 98
Joined: Thu Jul 25, 2019 12:16 am

Re: pH values of weak and strong acids

Postby Karina Kong 2H » Sun Jan 19, 2020 2:40 pm

Since weak acids do not dissociate as much as strong acids, there is a smaller concentration of H+ ions in weak acids, leading to a higher pH.

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

Re: pH values of weak and strong acids

Postby Anokhi Patel 2B » Sun Jan 19, 2020 3:40 pm

Acids with higher pH levels take longer to dissociate, therefore they solution is less neutral. So overall stronger acids are easily broken down in a reaction compared to weak acids.

Jocelyn Thorp 1A
Posts: 103
Joined: Wed Sep 18, 2019 12:20 am

Re: pH values of weak and strong acids

Postby Jocelyn Thorp 1A » Sun Jan 19, 2020 4:24 pm

pH is a -log[H+], which simply means that a lower pH is actually associated with a higher number of H+ ions. So saying a weaker acid has a higher pH actually means it has a lower concentration of H+ ions.

Catherine Daye 1L
Posts: 104
Joined: Wed Sep 11, 2019 12:16 am

Re: pH values of weak and strong acids

Postby Catherine Daye 1L » Sun Jan 19, 2020 4:45 pm

Acids make solutions that have a pH from 1-7, stronger acids making lower pH values than weak acids. pH doesn’t depend on concentration, but the strength of the acid/base.


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