Buffers

What are buffers?

A solution of a weak acid and its salt (or a weak base and its salt^33.1), which by its presence resists changes in pH.

What classic buffer system is found in the blood?

$$CO_{2} + H_{2}O \rightleftharpoons H_{2}CO_{3} \rightleftharpoons H^{+} + HCO_{3}^{-}$$ (33.10)

This buffer system plays a big role in the acid-base balance in the blood. The kidney is involved in $excreting$ bicarbonate (HCO$_{3}^{Ð}$) and also contains the enzyme carbonic anhydrase in the proximal tubule that catalyzes this reaction.

What is the effect of a buffer system on a titration curve?

Buffers increase the amount of acid or base required to change the pH.