"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 great example of a buffered solution is your blood. It is the combination or presence of carbonic acid (H₂CO₃) and bicarbonate (HCO₃^-) in the blood that keeps the pH of the blood in the proper range (Source).

In the table below, the masses give 0.1 M concentrations of each species, when diluted to 1.0 L, so that the [acid]:[conjugate base] ratio is unity. In most cases the pH will have to be adjusted using a pH meter and the dropwise addition of either 6 M HCl or 6 M NaOH to one liter of solution until the desired pH is reached.