What is a buffer solution?
A buffer solution or hydrogen ion buffer is defined as an aqueous solution comprising a mixture of a weak acid and its conjugate base, or vice versa. There is a change in pH when a small amount of strong base or acid is added.
What is buffer capacity?
The ability of buffer to resist pH change of solution on adding hydroxide ions. It is also called buffer index, buffer efficiency, buffer coefficient or buffer value.
The symbol ‘ β denotes it’. The buffer capacity decreases as the purity of fresh water increases.
Types of buffer solution
There are two types of pH buffers. They are:
- Solutions of single substances: A salt solution of a weak base and weak acid. Example CH3COONH4 (ammonium acetate)
- Solutions of Mixtures: These are further divided into two,
- Acidic buffer: These have a pH below 7 and comprise a weak acid and one of its salts. For example, a mixture of sodium acetate and acetic acid acts as a pH buffer with a pH value of about 4.75.
- Basic buffer or alkaline buffer: These have a pH value above 7 and comprise a weak base and one of its salts. For example, a mixture of ammonium hydroxide and ammonium chloride acts as a buffer solution with a pH value of about 9.25.
Buffer solution preparation
By knowing the pKa of the acid and pKb of the base, you can make a buffer of known pH by controlling the ratio of salt and base or salt and acid. Buffers are prepared by mixing a weak base with its conjugate acid or a weak acid with its conjugate base.
For example, a widely used buffer in laboratories, phosphate buffer, consists of a weak base and its conjugate acid. Its pH value is 7.4.
Uses of buffer solution
- Buffers are widely used in industrial processes such as fermentation and controlling dye.
- It is used in the manufacturing of pharmaceuticals.
- The human body uses buffers to maintain a blood pH of 7.35 to 7.45.
- Enzymes require precise pH levels to react properly.
For interactive and interesting content on Buffer solution or any other chemistry topics such as organic chemistry, register to BYJU’S – The Learning App.
- How To Stay Motivated To Study and Rank Higher
- Should You Go for Child Plans as Education Cost Shoots Up?
- 7 Tips to Crack MNC Interview
- 3 Reasons Why You Should Learn Spanish
- 6 Things To Know Before Pursuing A Degree In Biology