Acid Base Question

[fishsticks2629]

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I had the BR books that has really good chapters on Acid and Base, but some dbag stole it.
Can anyone tell me all the ways to derive Weak Acid Ph's??
Also can anyone tell me another way to derive the equivilance point for a weak acid/base with a strong acid/base titration?
The BR books also go over how to calculate the Ph at all the points of wek acid/base titration, if anyone has that and could tell me, it would be appreciated.. Thanks!!🙂

 

[PAOrtho]

its called google, dude

 

[fishsticks2629]

its called google, dude

Its called I already went on google and didn't want to waste time filtering through the bs. I figured it would be easier to have someone like you who doesn't have a life to just tell me.. I guess I was mistaken.

 

[LostInStudy]

Its called I already went on google and didn't want to waste time filtering through the bs. I figured it would be easier to have someone like you who doesn't have a life to just tell me.. I guess I was mistaken.

Lol. That's funny as hell because you probably thought that/it's probably true about most of us. With that said, you're probably not going to get any help now for pointing that out.

-LIS

 

[CaptainSSO]

pH = -log[H+] = log (1/[H+])

For a weak acid, ie: CH3COOH (acetic acid), first calculate Ka, so Ka = ([H+][CH3COO-])/[CH3COOH]).

Since a weak acid doesn't completely dissociate in solution, assume Ka = ([x][x]/[CH3COOH - x]); For the MCAT, assume x is small compared to CH3COOH, so Ka = (x^2)/[CH3COOH]). Plug in the Ka for acetic acid, multiply by [ ] of acetic acid, and take the square root, ie: (Ka*[CH3COOH])^(1/2) = [H+]... then -log[H+] gives pH.

Calculating the equivalence point should not show up on the MCAT since it's such a lengthy calculation, but it's the point where the number of mols of titrant added equals the number of mols of the starting acid/base being titrated. Of course, since you have so much of a life, grasping this information may be a bit complicated for you.

Someone please correct me if I have supplied our friend with any inaccurate information.

Edit: Not sure why the gay smiley face is at the top of my post. Not that it matters, but how do I get rid of that?