pH is one of the most common discussions in biology that it is hard for you to miss. Even without a scientific background, you will encounter the term “pH” just by going to the doctor once in a while as well as when you get a blood check.
pH is closely tied with acids and bases which describe the acidity or the alkilinity of a solution. It is a scale of 1 to 14 with 7 being a neutral solution. When a solution’s pH is below 7, this means that it is acidic. If it’s above 7, then the solution is alkaline.
Obviously, not all solutions remain in their ideal pH level. Take, for example, your blood. Your blood has a certain pH level and changes in it can result in positive or negative effects. That is why a buffer is needed in order to resist volatile changes in pH.
This buffer is called a buffer solution. A buffer solution is a mixture that either has a weak acid with its conjugate base or vice versa. A conjugate counterpart is needed because it gives the solution the ability to resist any changes in pH. Without the conjugate acid (or base), the solution will just be like any other which is susceptible to pH change.
The Types of Buffer Solutions
There are two major types of buffer solutions – acidic and alkaline which will be discussed together with buffer solution examples.
- Acidic Buffer Solutions
An acidic buffer solution is a solution that has a pH level below 7. This means that it is made up of a weak acid and its conjugate base. It also contains one of the salts of the acid. A common example of this kind of buffer solution is sodium acetate.
Sodium acetate is a solution made up of a weak acid (acetic acid) and one of its salts (sodium acetate). The sodium acetate gives the solution resistance to changes in pH. The solution’s pH then is 4.76. If you put this into a chemical equation, you will notice that the left side is not ionized completely. So, when you increase the ratio of the sodium acetate, the ions will go towards the left because this needs to be in equilibrium to the opposite side which ionized completely.
- Alkaline Buffer Solutions
On the other hand, an alkaline buffer solution is a solution that has a pH level above 7. So, this contains the opposite of what an acidic buffer solution has, namely, a weak base and its salt. One example of this solution is ammonium chloride.
Ammonium chloride is made of a base (which is ammonia) and its salt (chloride). When ammonia ionizes, it creates ammonium and hydroxide ions. Translated to a chemical equation, the right side contains ammonium ions and hydroxide ions.
Buffer solutions can be witnessed in real life and not just in chemical equations. An example of a buffer solution is a carbonate buffer solution found in the blood which helps maintain its pH. Since carbon dioxide released by the body is acidic, it will then react with blood (a weak base) to maintain pH levels.