Question

give the basicity of : nitric acid,sulphuric acid and phosphoric acid?

Answer 1

basicity of nitric acid is 1 , sulphuric acid is 2 and phosphoric acid it is 3.

Answer 2

One is thebasicity of HNO3. HNO3 is also known as mono basic as the basicity is one.(nitric acid)

Sulphuric acid

The basicity of an acid is equivalent to the number of H+ produced by an acid, when it gets ionized in the aqueous medium. So, forsulphuric acid, it is 2. 

phosphoric acid

Basicity of an acid refers to the number of replaceable hydrogen atoms in one molecule of the acid. As you can see in the above image of structure of H3PO4, there are 3 OH's attached. Thus the basicity of H3PO4 is also 3.(phosphoric acid)

hope it helps