Table of Contents
Introduction: What is a Buffer Solution?
A buffer solution is a solution that resists changes in pH. This is due to the presence of a large concentration of a weak acid and its conjugate base or a large concentration of a weak base and its conjugate acid.
Buffer Solution Definition
A buffer solution is a solution that resists changes in pH. This is because it contains a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid.
Mechanism of Buffering Action
Buffering is the process of neutralizing acids and bases. Buffers work by exchanging protons with hydroxide ions. This process prevents pH from changing and maintains equilibrium.
Preparation of Buffer Solution
A buffer solution is a solution consisting of a weak acid and its conjugate base, or vice versa. The buffer capacity is the ability of a buffer solution to resist changes in pH on the addition of small amounts of acid or base.
The preparation of a buffer solution begins with the identification of the weak acid and its conjugate base. Once these are identified, the appropriate amounts of each are mixed together to form the buffer solution. Buffers are created by combining a weak acid and its conjugate base. For example, acetic acid (CH3COOH) and sodium acetate (CH3COO-Na+).
The pH of a buffer solution is determined by the ratio of the weak acid to its conjugate base. For example, a buffer solution with a ratio of 1:1 will have a pH of 7. A buffer solution with a ratio of 2:1 will have a pH of 6.
Types of Buffer Solution
There are three types of buffer solution: weak, strong, and universal.
Weak buffer solutions contain a low concentration of acid or base. They are used to maintain the pH of a solution within a narrow range.
Strong buffer solutions contain a high concentration of acid or base. They are used to maintain the pH of a solution within a narrow range.
Universal buffer solutions can be used to adjust the pH of a solution in either direction.
Buffer Solution Examples
The following are examples of how to make a 0.1 Molar solution of sodium chloride, potassium chloride, and magnesium chloride.
0.1 Molar Sodium Chloride Solution
To make a 0.1 Molar sodium chloride solution, dissolve 0.1 mole of sodium chloride in 1 liter of water.
0.1 Molar Potassium Chloride Solution
To make a 0.1 Molar potassium chloride solution, dissolve 0.1 mole of potassium chloride in 1 liter of water.
0.1 Molar Magnesium Chloride Solution
To make a 0.1 Molar magnesium chloride solution, dissolve 0.1 mole of magnesium chloride in 1 liter of water.
Importance of Buffers
Buffers are important in biochemistry because they resist changes in pH by either supplying protons or accepting protons as needed. Buffers are necessary in order to maintain the stability of proteins and other biomolecules.
