The term dibasic acid is commonly referred to any substance that can donate two protons or hydrogen (H+) ions per molecule in an acid base reaction.
Due to this property, the dibasic acid is also known as diprotic acids.
A dibasic acid yields two free hydrogen ions in solution for each molecule of acid ionized or in other terms, has two replaceable hydrogen atoms.
A simple example of a dibasic acid is sulphuric acid (H2SO4).
H2SO4 → 2H+ + SO42-
Other examples of dibasic acids are as follows i.e. Carbonic acid (H2CO3) and Oxalic acid (C2H4H2) etc.