Question

Which of the following amines is not represented by formula \(\text{C}_3\text{H}_9\text{N}\) ?

• A. \(1^{\circ}\) amine
• B. \(2^{\circ}\) amine
• C. \(3^{\circ}\) amine
• D. quaternary ammonium salt

Hint:

C3H9N can be a primary, secondary or tertiary amine, but a quaternary ammonium salt has four carbon groups on N.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Amines are classified as 1, 2 or 3 degree by how many alkyl groups are on N. A quaternary ammonium salt has four groups and a positive charge, so it is not an amine.

Step 2: Detailed Explanation
Primary: \(\text{CH}_3\text{CH}_2\text{CH}_2\text{NH}_2\) (propylamine) and isopropylamine, formula \(\text{C}_3\text{H}_9\text{N}\).
Secondary: \(\text{CH}_3\text{NHCH}_2\text{CH}_3\), also \(\text{C}_3\text{H}_9\text{N}\).
Tertiary: \((\text{CH}_3)_3\text{N}\), also \(\text{C}_3\text{H}_9\text{N}\).
A quaternary ammonium salt needs at least four carbons, as in tetramethylammonium, so it cannot match.

Final Answer:
A quaternary ammonium salt is not represented by \(\text{C}_3\text{H}_9\text{N}\), option (D). \[ \boxed{\text{Quaternary ammonium salt}} \]