What is the Difference Between Monoprotic and Polyprotic Acids?

The main difference between monoprotic and polyprotic acids lies in the number of protons they can donate.

Monoprotic acids can donate only one proton, and they usually have only one hydrogen atom in their formula. Examples of monoprotic acids include:

• HCl (hydrochloric acid)
• CH3COOH (acetic acid)
• HNO3 (nitric acid)

Polyprotic acids can donate more than one proton. They can be further categorized into diprotic acids (can donate two protons) and triprotic acids (can donate three protons). Examples of polyprotic acids include:

• H2SO4 (sulfuric acid)
• H3PO4 (phosphoric acid)
• C10H16N2O8 (Ethylenediaminetetraacetic acid, or EDTA for short)

Polyprotic acids dissociate one hydrogen proton at a time, leading to multiple dissociation constants (e.g., (K{a1}), (K{a2}), (K{a3}) for diprotic acids). In contrast, monoprotic acids have only one dissociation constant (e.g., (Ka) for monoprotic acids).

Comparative Table: Monoprotic vs Polyprotic Acids

The main difference between monoprotic and polyprotic acids lies in the number of protons they can donate. Here is a table summarizing the differences between monoprotic and polyprotic acids:

Monoprotic acids can release only one proton per molecule and have one equivalence point. Polyprotic acids, on the other hand, can donate multiple protons per molecule and have several equivalence points, depending on the number of times dissociation occurs.