Buffer Solution: Definition, Applications, and Examples

Definition of Buffers

A solution that tends to resist changes in pH is called a buffer solution. Buffer solutions are the solutions that resist changes in the concentration of hydronium ion and hydroxide ion (and therefore pH) when adding low amounts of acid or base, or when diluting the solution.

Regulated solutions are used to maintain pH at a constant degree in a large number of chemical applications. saline, a weak base, and salts are acid.

Importance of Buffers

In the human body, pH varies from liquid to liquid, for example, in the blood is 7.4, whereas, in the infectious juices 1.5, these values are considered appropriate and ideal for the work of enzymes and balancing Osmotic pressure.

These values are often maintained by structured solutions, and the most important solution is phosphate and bicarbonate.

Buffer Solution Capacity

Reflect the resistance of the regulated solution to the change in pH, and the largest possible when the ratio between the acid and the associated base is equal to one.

Examples: include acetic acid CH3COOH is a weak acid and its associated base is sodium acetate CH3COONa.

Uses and Examples of Buffer Solution in Everyday Life

the use of the buffers is an important part of the many industrial processes, such as electroplating, manufacturing of leather, etc.
buffers are used extensively in analytical chemistry and are used to calibrate pH.
Human blood is buffered to a pH of 7.3. by the means of bicarbonates, phosphates, and complex protein systems.

Preparation of Buffer Solution

A buffer solution Preparation is specified pH values are prepared by half neutralization of the weak acid (e.g. CH₃COOH) with a strong base (NaOH) or a weak base (NH₄OH) with a strong acid (HCl).

A buffer solution of Acetic Acid and Sodium Acetate (Acidic Buffer)

Acetic acid dissociates to give acetate in a follows:

CH₃COOH ======== CH₃COO^– + H⁺

Sodium acetate dissociates to give also acetate ions as follows:

CH₃COONa ======== CH₃COO^– + Na⁺

When these two are mixed to make a buffer. There is an increase in the concentration of acetate ions. Acetic acid equilibrium is pushed to the left. So, H⁺ concentration is reduced and un-dissociated acetic acid is formed and there is no change in pH of the mixture.

how does the buffer solution works?

Case I: Study the effect of adding HCl to the solution:
1. The addition of HCl means the addition of H + and thus increasing the concentration of H3O + in the solution of the equilibrium Vichtel.
2. In accordance with the Leucatlier principle, the reaction (1) will be moved to the left by the excess H3O reaction with the CH3COO.
3. As a result of the displacement of the reaction (1) to the left, the effect of the increase in H3O concentration resulting from the addition of HCl will almost be eliminated and therefore the pH value of the solution remains almost constant.

Effect of Addition of Acid

In the case of added acid, additional H⁺ ions in the solution will combine acetate ions (CH₃COO) to produce un-dissociated acetic acid and pH will remain the same.

CH₃COO ^_ + H⁺ CH₃COOH