Question

How many primary amines are possible for the formula C$_4$H$_{11$N?}

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

For counting isomers of amines, remember: n-butyl, sec-butyl, isobutyl, and tert-butyl give four distinct primary amines for C$_4$H$_{11}$N.

Answer 1

The Correct Option is D

The general formula for a primary amine is R–NH$_2$. For molecular formula C$_4$H$_{11}$N, we must arrange 4 carbons into different alkyl groups attached to –NH$_2$.

Step 1: Straight chain amines. 1. n-Butylamine: CH$_3$–CH$_2$–CH$_2$–CH$_2$–NH$_2$
2. Isobutylamine: (CH$_3$)$_2$CH–CH$_2$–NH$_2$

Step 2: Branched chain amines. 3. sec-Butylamine: CH$_3$–CH(NH$_2$)–CH$_2$–CH$_3$
4. tert-Butylamine: (CH$_3$)$_3$C–NH$_2$

Step 3: Count unique structures.
Thus, four distinct primary amines are possible.
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