View source for Buffer solution

{{Acids and Bases}}
A '''buffer solution''' is chemical solution which resists change to its [[pH]] or acidity.

It is a [[solution]] in water of a mixture of a [[weak acid]] or [[Base (chemistry)|base]] and its salt. The [[pH]] of the solution changes very little when a small amount of [[strong acid]] or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. Many life forms have a relatively small pH range; an example of a buffer solution is [[blood]].

Buffer solutions may be of two types: acidic and basic.
*Acidic : A solution of mixture of weak acid and a salt of this acid with a strong base. 
eg. CH3COOH+CH3COONa
*Basic : A solution of a mixture of weak base and its salt with a strong acid .
eg. NH4OH+NH4Cl

If you add acid to the solution, the concentration of H+ ions will increase; to keep equilibrium a small number of ions will be combined (forming salt and reducing the concentration of H+ ion in the solution). If you add base the concentration of H+ ion will reduce (by consumption  or combining) and so a small amount of salt will break into ions and maintain the pH.

Buffer index is the number of moles of acid or base added to 1 litre of buffer solution to change its ph by 1 unit

{{chem-stub}}

== Buffer Solution Media ==
<gallery widths='160px' heights='100%' mode='traditional' caption=''>
File:Buffer titration graph.svg|Figure 1. Simulated [[titration]] of an acidified solution of a weak acid ({{math|1=p''K''a = 4.7}}) with alkali

File:Buffer Capacity 2.png|Figure 2. Buffer capacity ''β'' for a 0.1&nbsp;M solution of a weak acid with a p''K''a&nbsp;=&nbsp;7

File:TAPS.svg|Structure of TAPS (3-(Tris(hydroxymethyl)methylamino)-1-propanesulfonic acid)

File:Bicine.png|chemical structure of bicine (N,N-Bis(2-hydroxyethyl)glycine; Diethylolglycine; Diethanol glycine; Dihydroxyethylglycine)

File:tris.png|chemical structure of TRIS

File:Tricine.svg|Chemical diagram for tricine

File:TAPSO.svg|Structure of TAPSO (2-Hydroxy-3-[tris(hydroxymethyl)methylamino]-1-propanesulfonic acid)

File: HEPES.png|Chemical Structure of 4-(2-Hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES).

File:TES free acid.svg|Structure of TES (buffer); TES free acid; N-Tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid

File:Mops is.svg|3-(N-morpholino)propanesulfonic acid
</gallery>
{{Chemical solutions}}

[[Category:Acids]]