Why Should We Care?
The general conjugate acid-base equation for equilibrium,
where HA is the acid and A- is the conjugate base, is a very useful equation. Using this equation, chemists can quickly calculate the ratio between the acid and base as long as the [H3O+] of a solution (determined by measuring pH) and the Ka of the acid (found in tables of Ka values) are known. Alternatively, the pH of an acid/base solution can be easily found if the ratio of the acid and base concentrations are known. This has many useful applications in industry, biology and medicine.
For instance, carbonic acid, hydrogen carbonate ions and carbonate ions not only regulate ocean pH, but they are also involved in an important buffer in human blood that minimizes changes in blood pH. The acid-base equilibrium equation can be used to determine the ratio of these species that is required to maintain a suitable pH in the blood. Acidification of body tissues, called acidosis, is a very serious condition. It is important for health care professionals to know the ratio of acid-base species required in the body.