A buffer solution is water mixed with a chemical to give it special properties in regards to pH (acidity). The chemical, known as a buffer agent, resists pH changes when exposed to acids and bases when properly mixed in a solution. This property makes it extremely useful in protecting sensitive equipment, dealing with chemical accidents, and even in balancing the internal processes of living things. A buffer agent’s acid form (HA) is mixed with its conjugate base (A-) in water to make the solution. Once a balance exists between HA and A-, any other acids or bases added will be neutralized when they turn a portion of the buffer agent into either the HA or A- form. The change in the buffer agent initially causes little change in the solution’s pH. As the proportion of the agent’s HA and A- changes due to the addition of other acids and bases, the buffering capacity of the solution decreases. Eventually, a buffer agent can be used up to the point where it can no longer significantly resist pH changes, meaning it is no longer useful for this purpose.