what is buffer solution and what does it do?

Question

my bio class did an experiment to find the realtionship of PH level with enyme activity.
apparently, the buffer solution was used in the experiment for something about PH.
so my questions are, what is a buffer solution?
what does a buffer solution do?
and does a buffer solution speed up chemical reactions?
tell me everything you know about buffer solutions.
thank you!

please don't quote from wikipedia because i didn't understand their explanation.

i didn't understand what "it resists the change of Ph" meant...

Answer 1

A buffer solution has pairs of salts of weak acids or weak bases in it. An example is Na2CO3/NaHCO3. If you add HCl to the solution, it reacts HCl + Na2CO3 ===> NaHCO3 + NaCl. So you don't get the full force of the H+ driving down the pH. Likewise, if you add a bit of NaOH, NaOH + NaHCO3 ===> Na2CO3 + H2O. So the pH doesn't rise drastically.

You have to go back to your lab to find out the pair of salts you used as a buffer.

Answer 2

A buffer answer is composed of a vulnerable acid and a salt of its conjugate base (somewhat, eliminate a hydrogen) or a vulnerable base and a salt of its conjugate acid (upload a hydrogen). the 1st is proper. it somewhat is a vulnerable acid (CH3COOH) and a salt of the conjugate base (a salt of the acetate ion, for this reason sodium acetate), so it satisfies the situations. the 2d isn't proper. whilst it somewhat is an acid and a salt of the conjugate base, the acid, HCl, is a robust acid, no longer a vulnerable one. The 0.33 is proper. it somewhat is a vulnerable base (NH3, genuinely THE classic vulnerable base for chem instructions) and a salt of its conjugate acid (NH4+; the salt is NH4Cl), so the situations are happy. The fourth isn't proper, because of the fact it is not a conjugate acid-base pair. somewhat, the two are bases. i'm hoping this permits.

Answer 3

http://en.wikipedia.org/wiki/Buffer_solution