Question

Identify the most basic compound from the following:

• A. Primary amines
• B. Secondary amines
• C. Aromatic amines
• D. Aliphatic amines

Answer 1

The correct option is B

Secondary amines

The explanation for the correct answer:-

Option (B) Secondary amines

• Due to the presence of nitrogen atoms, amines are basic in nature.
• The basic nature of amines depends on Nitrogen's lone pair of electrons.
• The higher the electronic effect on the lone pair of nitrogen higher will be the basicity.
• Amines act as a Lewis base (can donate a pair of nonbonding electrons) because when a ${\mathrm{H}}^{+}$ ion approaches amines, nitrogen donates its lone pair to the ion.

• Thus secondary amines are the most basic amines among all the compounds.
• Hence, Option B Secondary amine is correct.

Explanation for incorrect answer:-

Option (C) Aromatic amines

• The lone pair present on nitrogen atoms in aromatic amines will take part in the resonance of the ring, so the availability of lone pairs is less in aromatic amines. Hence aliphatic amines are more basic than aromatic amines.

• Hence Option C is incorrect.

Option (A) Primary amines

• Primary amines are less basic than secondary amines.
• Due to a less inductive effect, the protonation of amines becomes less efficient.

• Hence Option A is incorrect.

Option (D) Aliphatic amines

• In aliphatic amines, no such resonance takes place so they are more basic than aromatic amines.

• Therefore, aliphatic amines are more basic than aromatic amines.
• In aliphatic amines, the secondary amine is more basic.
• Hence Option D is incorrect.

Therefore, option (B) is the correct answer.