These types of titrations revolve around the three or more Ka values of the polyprotic acid. 

Polyprotic Acid Titrations

Concept #1: Triprotic acids are the most commonly used polyprotic acids and revolve around 3 equivalence points and equivalence volumes. 

 

 

Concept #2: Before the first equivalence point has been reached we have the formation of a buffer region. 

Concept #3: At the first equivalence point we now have an excess of the first intermediate form for the polyprotic acid. 

Concept #4: Before the second equivalence point has been reached we have the formation of another buffer region. 

Concept #5: At the second equivalence point we now have an excess of the second intermediate form for the polyprotic acid. 

Concept #6: After the second equivalence point there is an excess of the strong base and the basic form of the polyprotic acid.