Question

Why is Benzoic acid the stronger acid than 2-Naphthol?

Answer 1

Benzoic acid and 2-Naphthol:

1. Benzoic acid has a chemical formula ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CO}}_2\mathrm{H}$.
2. 2-Naphthol has a chemical formula ${\mathrm{C}}_{10}{\mathrm{H}}_7\mathrm{OH}$.
3. The structures are given below:

Strongest acid:

1. Benzoic acid is a weak acid since it is an organic acid.
2. Acid signifies that it leaves protons in an aqueous solution.
3. The acid is stronger when the proton-leaving rate is high.
4. Benzoic acid is more strongly acidic than 2-Naphthol due to the high amount of Hydrogen (${\mathrm{H}}^{+}$) ion donation. Benzoic acid can donate ${\mathrm{H}}^{+}$ with ease because benzoate ion formed is resonance stabilised.
5. In most cases, acidic organic molecules are extracted as $\mathrm{NaOH}$ using an aqueous inorganic base solution.
6. Both benzoic acid (a carboxylic acid) and 2-Naphthol (a weak acid) are ionized into salt in the presence of $\mathrm{NaOH}$, which is a solid inorganic base.

Hence, Benzoic acid is the strongest acid than 2-Naphthol.