Buffers can be made from weak acids or base and their salts. For example, if 12.21 grams of solid sodium benzoate are dissolved in 1.00 L 0.100 M benzoic acid (C6H5COOH, pKa = 4.19) solution, a buffer with a pH of 4.19 will result: Buffers can be made from two salts that provide a conjugate acid-base pair.

A buffer is made by mixing a large volume of a weak acid or weak base together with its conjugate. A weak acid and its conjugate base can remain in solution without neutralizing each other. The same is true for a weak base and its conjugate acid.

A biological buffer is an organic substance that has a neutralizing effect on hydrogen ions. In this way, a biological buffer helps maintain the body at the correct pH so that biochemical processes continue to run optimally. Most buffers consist of a weak acid and a weak base.

The two primary types into which buffer solutions are broadly classified into are acidic and alkaline buffers.

• Acidic Buffers.
• Alkaline Buffers.
• On Addition of Acid and Base.
• Preparation of Acid Buffer.
• Preparation of Base Buffer.
• Significance of Handerson Equation.
• Limitations of Henderson-Hasselbalch Equation.

Buffers should be made using an acid and its conjugate base (or a base and its conjugate acid ); the pair should have a Ka very similar to the desired pH. The exact ratio of the conjugate base to the acid for a desired pH can be determined from the Ka value and the Henderson-Hasselbalch equation.

What Makes a “Good” Buffer?

1. A pKa between 6 and 8.
2. Solubility in water.
3. Exclusion by biological membranes.
4. Minimal salt effects.
5. Minimal effects on dissociation from changes in temperature and concentration.
6. Well defined or nonexistent interactions with mineral cations.
7. Take home message: Buffers are not inert.

Buffers are broadly divided into two types – acidic and alkaline buffer solutions. Acidic buffers are solutions that have a pH below 7 and contain a weak acid and one of its salts. For example, a mixture of acetic acid and sodium acetate acts as a buffer solution with a pH of about 4.75.

Stability. Buffers are often used in research on reactions involving enzymes. A Good buffer is chemically stable enough to resist degradation that enzymes could cause. Furthermore, a Good buffer is also resistant to non-enzymatic degradation by other components of the setup.

The body uses buffers solution to maintain a constant pH. For example, blood contains a carbonate/bicarbonate buffer that keeps the pH close to 7.4. Enzyme activity depends on pH, so the pH during an enzyme assay must stay constant. In shampoos.

Because water is made of hydrogen and oxygen, it can dissolve to release both hydroxide (basic) and hydronium (acidic) ions, making it a natural buffer solution. This means that water can neutralize to some extent either an acid or a base; additionally, water is an excellent diluent for both acids and bases.

What is a buffer solution? If you add a small quantity of strong acid or strong base to water there will be a large change in pH . Conclusion: water is not a buffer.

Why isn’t water a good buffer? Because there is no conjugate base (A- in the case of the acid HA), which you need in addition H+ to be a buffer. The concentration of OH- is so low that it can’t absorb very much added H+ , and the concentration of H+ is too low to absorb very much added base. Water is a good buffer.

The three major buffer systems of our body are carbonic acid bicarbonate buffer system, phosphate buffer system and protein buffer system.

Biological Buffers: Reviewing the Basics Upon the addition of a strong base such as NaOH to the buffer solution, the hydrogen ion will bind with the hydroxide ion to form water. Upon the addition of a strong acid, however, the conjugate base will simply bind with the additional hydrogen ions to form acetic acid.

(1) The pKa of the buffer should be near the desired midpoint pH of the solution. (2) The capacity of a buffer should fall within one to two pH units above or below the desired pH values. If the pH is expected to drop during the procedure, choose a buffer with a pKa slightly lower than the midpoint pH.

Here we examine the basic chemistry of buffer systems and how that chemistry applies to reactions in experimental biological systems. Buffers consist of a weak acid (HA) and its conjugate base (A–) or a weak base and its conjugate acid.