A buffer solution can be defined as an aqueous solution that is made up of a mixture of a weak acid and the conjugate base of that weak acid. Alternatively, buffer solutions can also feature a weak base and the conjugate acid of that weak base. Buffer solutions are also referred to as pH buffers and sometimes as hydrogen ion buffers. The functionality served by buffer solutions is to resist any changes in pH brought on from the external environment. Buffer solutions typically exhibit a very small pH change when strong acids or strong bases are added to them. Since they have the ability to maintain the pH of an environment to an almost constant value, these solutions are known to have a wide range of applications in the field of chemistry. Some important properties and applications of buffer solutions are provided in this article.
The Principle behind Buffer Solutions
Buffer solutions tend to resist changes in pH as a result of the equilibrium that exists between the weak acid and the conjugate base (or alternately, the weak base and the conjugate acid) that make up the solution. Follow the link to learn about the pH scale and the definition of pH. When a strong acid is introduced to a mixture of a weak acid and its conjugate base (in a state of equilibrium), the increase in the concentration of hydrogen ions causes the equilibrium to shift to the left. This occurs due to Le Chatelier’s principle of chemical equilibrium. Consequently, the increase in the hydrogen ion concentration (as a result of the addition of the strong base to the buffer) is relatively low for the amount of the strong acid that is added. The effect is quite similar (but involving an equilibrium shift in the opposite direction) when a strong base or a strong alkali is added to the buffer solution.
Applications of Buffer Solutions
For the smooth occurrence of several bodily functions in biological systems, it is vital to maintain a pH balance. For example, the regulation of the pH inside the body is very important for the proper functioning of enzymes. Human blood is known to contain a mixture of bicarbonates and carbonic acid in the plasma fraction. These two ions are responsible for forming a buffer solution that regulates and maintains a pH range of 7.35 to 7.45 in blood. If the pH of the blood increases above the upper limit of this range, it is not uncommon for acidosis to occur in the body, which is known to negatively affect the metabolism in the body. Similarly, if the pH of the blood drops below the lower limit, a condition known as alkalosis is developed, which also negatively affects the healthy metabolism cycle in the body. It can also be noted that the pH of a buffer solution can be estimated with the help of the Henderson-Hasselbalch equation. Thus, buffer solutions are vital for a large number of life forms on this planet. The range of buffer solutions can be extended via the addition of other buffering agents.