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Acid and Base Equilibria

Posted: Wed Jan 16, 2019 8:23 pm
by sonalivij
Why do solutions of weak acids have higher pH values than solutions of strong acids at the same concentration? Is it because a higher pH indicates a less acidic solution because the weak acid has not fully dissociated?

Re: Acid and Base Equilibria

Posted: Wed Jan 16, 2019 8:29 pm
by Grace Kim 1J
Like you said, weak acids do not dissociate 100%, so they will produce less H3O+, resulting in a higher pH value. The concentration of H3O+ will be lower than that of a stronger acid, since stronger acids almost always dissociates completely.

Re: Acid and Base Equilibria

Posted: Wed Jan 16, 2019 8:35 pm
by LilyL1C
Yes, that is correct. And the pH scale is set up so that 0 is acidic, 7 is neutral, and 14 is basic. So a weak acid's higher pH means that it is less acidic and more basic than the strong acid.

Re: Acid and Base Equilibria

Posted: Wed Jan 16, 2019 8:39 pm
by Alexa Tabakian 1A
A weak acid has a higher pH. A pH of 7 is neutral, so the weaker the base, the closer to 7 it gets.

Re: Acid and Base Equilibria

Posted: Wed Jan 16, 2019 8:54 pm
by charlotte_jacobs_4I
If you are saying higher pH in terms of numbers closer to 7 than yes you would be correct. If you think about a strong acid that has completely dissociated, the humber of H+ ions in that solution will be greater than that of a weak acid.

Re: Acid and Base Equilibria

Posted: Thu Jan 17, 2019 10:59 am
by Brian Kwak 1D
I also wanted to input that pH is also related to the concentration of Hydronium ions (H3O+). For example if you have a pH of 1 to convert that into concentration you would take the antilog of -1 (The reason you take the antilog is because pH=-log[H3O+] and we know that the ph is 1 so we solve for the concentration of H3O+.) When we convert it into concentration it would be 10^-1. So in respect to say pH 7. The hydronium concentration would be approximately 10^-7 for pH 7 and the concentration for pH 1 would be approximately 10^-1. When you compare both concentrations we can see that 10^-1 is larger than 10^-7. Hope this helps and clarified any confusion.

Re: Acid and Base Equilibria

Posted: Thu Jan 17, 2019 11:16 am
by megangeorge-1K
For this week should we be submitting homework from chapter 12?

Re: Acid and Base Equilibria

Posted: Thu Jan 17, 2019 11:37 am
by Zubair Ahmed 1L
megangeorge-1K wrote:For this week should we be submitting homework from chapter 12?

We can choose Hw questions from either Chemical Equilibria or Acids and Bases outlines.