Question

How can I determine the formula of an acid?

Answer 1

Hint: Acids are the chemical compounds available in nature in different types like binary acids and ternary acids. Acidic compounds are going to rust the metallic substances and make them to degrade.

Complete answer:
- In the question it is asked to determine the formula of an acid.
- Generally acids in nature exist in different forms like binary and ternary.
- The name of the Binary acids is going to start (prefix name) with “hydro” and ends with acid (depends on the second element present in it).
 - For example take HCl, it is a binary acid and the name of HCl is Hydrochloric acid. Here the second element is chlorine and in the acid name it is written as “chloric”.
- Coming to Ternary acids the name is not going to start with hydro, here the name is going to start (prefix) with polyatomic anion (which has a suffix with “ide”).
- The name to ternary acid comes from the element which is present as first in polyatomic ion.
- Coming to ${{H}_{3}}P{{O}_{4}}$, it is a ternary acid and the name is phosphoric acid. Because here the polyatomic ion is phosphate.
- Coming to ${{H}_{3}}P{{O}_{3}}$ , it is a ternary acid and the name is phosphorous acid. Because here the polyatomic ion is phosphite.

Note:
We should remember that if the polyatomic ion name is going to end with ‘ate’ then we should write the ‘ic’ in the name of the acid and if the polyatomic ion name is going to end with ‘ite’ then we should write the ‘ous’ in the name of the acid.