Buffer Solution

There are numerous applications in research and science where variations in pH can be severely damaging. One instance of this happens in the human body, where alterations to blood pH can become potentially fatal. However, an internal physical mechanism known as bicarbonate buffering maintains a constant blood pH.

In laboratories, it is common practice to do comparison tests using a buffer solution. Using a buffer solution helps keep the pH of the material under treatment under control, reducing the risk that any unwanted incidental effects may influence it and cause extra damage. A buffer solution contains a weak acid and its conjugate base or a weak base and its conjugate acid.

Buffer Solutions

To define a buffer solution, think of it as a solution of acid and base. The buffer solution is made by taking a weak acid and adding its conjugate base (formed by extracting a proton from the same acid) or combining a weak base with its corresponding acid. Using conjugates makes a buffer solution resistant to pH variations; it creates an acid-base equilibrium that is hard for other acids or bases to override. Even upon adding strong acids or alkalis, the equilibrium between the weak acid/base and its conjugate diminishes the addition’s impact on total solution pH.

Buffering pH

Buffer solutions provide a vast range of functions, both in reality and in the lab. For most proteins to function properly, a buffered pH is required, and this buffering is employed to guarantee adequate shading fixation when utilising coloured pigments. Furthermore, buffer solutions are used to correct devices, especially pH metres that might be miscalibrated, presuming a buffer is lacking. Remember that buffer solutions do not always have a neutral pH. Buffer solutions formed from citrus extracts, alkalis, acidic corrosives (which may be found in small amounts of vinegar) and other substances can have pH values of as low as two or as high as 10. These acids and bases may now be used in buffer solutions.

Buffer Capacity

Typically, buffer solutions are resistant to changes in pH. However, a strong enough acid or alkali can change the pH of a buffer solution. The buffer capacity is the amount of strong acid or base that can be added to a buffer solution before pH changes considerably. The capacity varies with the core components of the buffer solution and the quantity of strong acid or base added. Increasing the acid concentration increases the buffer solution’s capacity by the same factor, determining how much base is present in the solution. If adding a strong base, the capacity equals the amount of acid in the solution.

Overview of buffer solution

• Acidic buffer

Acidic buffer solutions have a pH of under 7 and are often the result of a combination of a weak acid and one of its salts. Some common acidic buffer solutions combine ethanoic corrosive and sodium ethanoate in solution, with a pH of 4.76 when blended in equivalent molar fixations. It is possible to alter the pH of the buffer solutions by changing the proportion of acid or by using another acid and one of its salts.

• Alkaline buffer

Basic buffer solutions have a pH higher than 7 and are derived from a weak base and one of its salts. Most of the commonly used alkaline buffer solutions are a mix of alkali and ammonium chloride solution. Assuming they were mixed in indistinguishable molar sums, the solution would have a pH of 9.25.

How does the buffer solution work?

When hydrogen ions are supplied to a buffer solution, they will be neutralised by the alkali in the solution. The acid will neutralise hydroxide ions. The buffer solution pH will not be significantly affected by these neutralising actions. When choosing an acid for a buffer solution, utilise an acid with a pKa around the required pH. This will give your buffer roughly identical amounts of acid and conjugate base, so it will be able to neutralise as much H+ and OH- as practical.

How to make a buffer solution?

A buffer solution is created by mixing a large volume of a weak acid or weak base and its conjugate. A weak acid and its conjugate base may exist in solution without neutralising each other. The same is true for a weak base and its conjugate acid.

Meaning of buffer solution with an example

A buffer solution or buffer combines a weak acid and its conjugate base. Strong acids and bases do not cause pH changes in buffer solution. In this case, the buffer is an acetic acid/sodium acetate solution CH3COOH + CH3COONa. A weak base and its salt is an example of a buffer, NH3aq + NH4Claq.

Conclusion

Buffer preparation is common in chemistry and biology laboratories. A buffer solution comprises a weak acid and its conjugate base. Buffer solutions help maintain the pH of another solution mixed with the buffer. When a little solution of a different acid or alkali is introduced, the buffer resists changes in the pH value of the whole solution. Buffer solutions are therefore useful in many situations where a constant pH is required. A buffer is also known as a buffer solution, pH buffer, or hydrogen ion buffer. Buffer solutions are extremely useful in a wide variety of applications. However, buffer preparation is time-consuming and labour-intensive and great care must be exercised to minimise error.