Question

How are buffer solutions used?

Answer 1

Hint: The buffer solution is added to the solution which resists the change in pH on addition of any acid compound or base compound. Buffer solution can be acidic buffer and alkaline buffer.

Complete step by step answer:
The buffer solution is defined as the solution which resists the change in pH in addition to solvent or any other chemical compound. The buffer solution is prepared by mixing weak acid and its conjugate base or weak base and its conjugate acid. Water is used as the solvent in preparation of buffer solution.
There are mainly two types of buffer, acidic buffer and alkaline buffer. The acidic buffer has acidic pH and is prepared by mixing weak acid and its salt with a strong base. Example of an acidic buffer is equal concentration of acetic acid and sodium acetate. It has a pH of 4.74. The alkaline buffer has basic pH and is prepared by mixing a weak base and its salt with strong acid. Example of an alkaline buffer is aqueous solution prepared by equal concentration of ammonium hydroxide and ammonium chloride. It has a pH of 9.25.
Buffer solution is mostly used during titration method and added in small amounts in the solution, so by addition of any other chemical compound, the solution does not change its pH.
The mechanism involved during the addition of buffer solutions in other solutions is shown below.
In solution, the salt completely breaks down to release its ions but weak acid does not completely break down to give its ion.
$C{H_3}COONa \rightleftharpoons N{a^ + } + C{H_3}CO{O^ - }$
$C{H_3}COOH \to {H^ + } + C{H_3}CO{O^ - }$
On adding acid, the protons released by the acid will be removed by the acetate ion released by the acetic acid.
${H^ + } + C{H_3}CO{O^ - } \rightleftharpoons C{H_3}COOH(from\;buffer\;solution)$
On adding base, the hydroxide ion released by the base is removed by the hydrogen ion and as a result water is formed.
$H{O^ - } + {H^ + } \rightleftharpoons {H_2}O(from\;buffer\;solution)$

Note:
Buffer solution is used in many laundry detergents to prevent their natural ingredients from breaking down. Paints and oils are buffered to maintain their standard industrial requirements.