Our body constitutes of many fluids for example blood, which has a well-defined value of pH as any change in the pH value results in malfunctioning of the body. For many biological and chemical processes to take place the pH control is very significant. There are many medical and cosmetic formulations which are supposed to be kept and administered only at a particular pH value. Buffer solutions are the ones which can resist change in pH value on dilution or addition of small quantity of acids or alkalis.
A buffer solution can be easily prepared if we know the value of pKa of an acid or pKb of a base and if the ratio of salt and acid or salt and base is controlled. A buffer solution basically resists the change in pH, in order to accomplish this task it should have a component that can react with acids or bases which might be added to the solution. If we simply add an acid and a base to form a buffer solution, then they will neutralize each other and will no longer have the ability to neutralize the acids or bases added later. Instead, for preparing a buffer solution we use weak acid and its salt (conjugate base) or a weak base and its salt (conjugate acid). There are cases in which acid salts also serve as buffer solution, for example NaH2PO4 .
The two most important properties while considering a buffer solution is buffer capacity and the pH range. The pH range is the determined pH value that the buffer solution has to maintain. The capacity of a buffer solution is said to be the amount of acid or base that a buffer solution can tolerate without much of a change in the pH value.
For example, if we take a mixture of acetic acid and sodium acetate, this will act as a buffer solution at pH 4.75 whereas at pH value of 9.25 the mixture of ammonium hydroxide with ammonium chloride acts as a buffer solution.
Now we have a fair idea about the buffer solution and its properties. The topic is very vast and if you are curious to explore more, please install Byju’s the learning app and get thrilled with the amazing experience of learning in the most innovative ways.