How do buffer solutions work...simple explanation please?

Answer 1

Buffer solutions are solutions which resist change in hydronium ion and the hydroxide ion concentration (and consequent pH) upon addition of small amounts of acid or base, or upon dilution. Buffer solutions consist of a weak acid and its conjugate base (more common) or a weak base and its conjugate acid (less common). The resistive action is the result of the equilibrium between the weak acid (HA) and its conjugate base (A−):

HA(aq) + H2O(l) ⇌ H3O+(aq) + A−(aq)

Any alkali added to the solution is consumed by hydronium ions. These ions are mostly regenerated as the equilibrium moves to the right and some of the acid dissociates into hydronium ions and the conjugate base. If a strong acid is added, the conjugate base is protonated, and the pH is almost entirely restored. This is an example of Le Chatelier's principle and the common ion effect. This contrasts with solutions of strong acids or strong bases, where any additional strong acid or base can greatly change the pH.

When writing about buffer systems they can be represented as salt of conjugate base/acid, or base/salt of conjugate acid. It should be noted that here buffer solutions are presented in terms of the Brønsted-Lowry notion of acids and bases, as opposed to the Lewis acid-base theory (see acid-base reaction theories). Omitted here are buffer solutions prepared with solvents other than water.

Applications

Their resistance to changes in pH makes buffer solutions very useful for chemical manufacturing and essential for many biochemical processes. The ideal buffer for a particular pH has a pKa equal to the pH desired, since a solution of this buffer would contain equal amounts of acid and base and be in the middle of the range of buffering capacity.

Buffer solutions are necessary to keep the right pH for enzymes in many organisms to work. Many enzymes work only under very precise conditions; if the pH strays too far out of the margin, the enzymes slow or stop working and can denature, thus permanently disabling its catalytic activity. A buffer of carbonic acid (H2CO3) and bicarbonate (HCO3−) is present in blood plasma, to maintain a pH between 7.35 and 7.45.

Industrially, buffer solutions are used in fermentation processes and in setting the correct conditions for dyes used in colouring fabrics. They are also used in chemical analysis and calibration of pH meters.

Answer 2

It is a solution that can have acid or base added to it without changing its pH. It however has a buffering capacity meaning a some point the addition of enough acid will turn the solution more acidic or the addition of enough base will turn the solution basic (alkaline). As far as contact lenses are concerned, buffer solutions are made that have a neutral pH (7) as not to damage your eyes. Acids or basic compounds are not good for mucus membranes.

Answer 3

How Do Buffers Work

Answer 4

A solution that contains a weak acid and its conjugate base or a weak base an its conjugate acid is known as a buffer solution. Such a solution can be prepared by mixing a solution of weak acid or weak base with one of its soluble salts, for eg:

CH3 COOH (aq) + CH3 COONa (aq) = acidic buffer.

NH4OH (aq) + NH4Cl (aq) = basic buffer.

Answer 5

It adjusts the pH of a solution. It makes the acidic or basic solution a certain pH, then makes it stay there.


a a a : say your source is wikipedia!