Acid and Base Equilibria

[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?

[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.

[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.

[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.

[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.

[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.

[megangeorge-1K]

For this week should we be submitting homework from chapter 12?

[Zubair Ahmed 1L]

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.