Question

How many primary amine isomeric forms are possible for the formula \(\text{C}_{4}\text{H}_{11}\text{N}\)?

• A. \(1\)
• B. \(2\)
• C. \(3\)
• D. \(4\)

Hint:

A primary amine is R-NH2, so count the possible butyl groups R.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
A primary amine has the form \(\text{R-NH}_2\). For \(\text{C}_4\text{H}_{11}\text{N}\), R must be a butyl group, \(\text{C}_4\text{H}_9\).

Step 2: Count the butyl groups
There are four different butyl groups: n-butyl, sec-butyl, isobutyl and tert-butyl.

Step 3: List the amines
There are four butyl groups, so four primary amines are possible:
butan-1-amine, \(\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{NH}_2\)
butan-2-amine, \(\text{CH}_3\text{CH}_2\text{CH(NH}_2\text{)CH}_3\)
2-methylpropan-1-amine, \((\text{CH}_3)_2\text{CHCH}_2\text{NH}_2\)
2-methylpropan-2-amine, \((\text{CH}_3)_3\text{CNH}_2\)

Final Answer:
Four primary amine isomers are possible, which is option (D). \[ \boxed{\text{(D) }4} \]