A combination of a weak acid and
its conjugate base which is a mix of a weak base and its conjugate acid is so-called
a buffer solution or a buffer. Buffer solutions repel a change in pH when small
amount of a strong acid or a strong base are additional. Therefore, the best
acid to use in the preparation of a buffer with pH=3.3 is HNO₂(Ka =
4.5 * 10 ⁻⁴). The pH of a buffer is contingent on the ration base /
acid relatively than on the particular concentration of a precise solution. The
precise ratio of the base to the acid for an anticipated pH can be determined
from the Ka value and the Henderson HasselBalch equation.
