[BloodCrisis]

Hello, again  , this time I'm having trouble with buffers...

"If you have to choose from this three acids (with their respective conjugate base salts), which one works better to regulate a 10^-4 "K" solution". The options were; Salicylic acid, carbonic acid and formic acid. And with your answer, later you have to solve an equlibrium problem.

I concluded that I can use both, Salicylic acid and Formic acid, but I used salicilic acid to solve the problem...

Well, what do you think? Which option is best? Its ok my answer?

Anyway thanks for reading!

[Borek]

No idea what is 10^-4 K solution and what pH do you need.

[BloodCrisis]

Haha Sorry

K---> Equilibrium Cosntant ----> http://en.wikipedia.org/wiki/Equilibrium_constant

[Borek]

Still no idea what it means. Buffer is not something to "regulate K=10^-4 solution", buffers are used to keep pH at some predefined level (or at least as close to that level as possible). I guess this is some twisted way of stating you are looking for buffer made with acid with pKa close to 4, but the way it is worded doesn't make any sense.

[BloodCrisis]

Yeah, I guess that's the idea, a buffer to regulate a pH
around 4. I also do not like the words she used, but matches the style of my teacher ...

Well, I'm translating this from spanish, consider that also... It's already hard to understand her in the original languaje...

[BloodCrisis]

I have more data...


PKa Formic acid:3.75
Pka salycilic acid:3
Pka Carbonic acid: 6,7 ------> Too far...

So by following the pka +-1 rule, the formic acid would be the best...  :-[too bad I used salycilic.