Question

phosphoric acid is which kind of substance. is it a dibasicaacidà or tribasic acid or diacidic Base or triacidic base ​

Answer 1

H3PO4, phosphoric acid, can be written O=P(OH)3. It has three acidic protons (attached to oxygen) and is therefore tribasic. Its salts are called phosphates. But H3PO3, phosphonic acid, has one of the hydrogens directly bound to phosphorus as O=PH(OH)2.
..........

Answer 2

It is a tribasic acid as it is likely to be more acidic in nature