Polyprotic Acids and Buffers

Henderson Hasselbalch equation

________ can be used to calculate the pH of a buffer.

Buffer capacity

________ depends on the number of moles of the weak acid and its conjugate base that are in the mixture.

Buffer solutions

________ resist changes in pH upon addition of a small amount of strong acid or base.

Monoprotic acids

acids that contain one ionizable hydrogen atom

Polyprotic acids

acids that contain more than one ionizable hydrogen atom

Buffer

a solution containing appreciable amounts of both a weak acid and its conjugate base (or a weak base and its conjugate acid)

The addition of OH

to a buffer converts an equimolar amount of Ha to A-

Remember that in a buffer,  [H+]  =   Ka (  (HA))/(A-)   ( HA and A

represent any acid and its conjugate base.)

Buffer capacity

amount of strong acid or base that can be added to a given volume of a buffer solution before the pH changes significantly

All buffers have a limited capacity of how much H3O+ or OH

they can "soak up."

Eventually, all the A

reacts with the added H3O+