Question

What is the ‘n’ factor of boric acid?

Answer 1

Hint: ‘n’ factor for acids and bases is different in meaning. For acid it is the number of replaceable hydrogen ions. While in bases it is the number of hydroxide ions replaced. The ions are replaced by acids in acid and bases in a base. Boric acid is termed as a weak acid, due to its less dissociation ability.

Complete answer:
Acids are the substance that has the ability to liberate hydrogen ions in solutions. The ‘n’ factor for any acid can tell us the number of replaceable hydrogen ions in that acid by 1 mole of the acid.
Boric acid has the formula ${{H}_{3}}B{{O}_{3}}$ , it is considered as a weak acid due to less dissociation in aqueous medium. The dissociation of boric acid in solution can tell us its ‘n’ factor by the product it can form. This can be calculated from the number of molecules of hydrogen it can liberate. So, the dissociation of boric acid in solution is:
${{H}_{3}}B{{O}_{3}}+2{{H}_{2}}O\to {{[B{{(OH)}_{4}}]}^{-}}+{{H}_{3}}{{O}^{+}}$
Since, only one hydrogen ion is dissociated that forms a hydronium ion with water, therefore the ‘n’ factor for boric acid is 1.
So, the ‘n’ factor of boric acid is 1.

Note:
The ‘n’ factor of 1 means boric acid is a weak monobasic acid. As sulfuric acid has n factor 2, it can replace 2 hydrogen ions so it is called a dibasic strong acid. This can be termed as the basicity of an acid, as the number of hydrogen ions will neutralize the base, so it can be told by basicity in terms of an acid being, mono, di, or tri basic.