Total number of 2° amine isomers of C4H11N would be (only structural) :A 4 B 3 C 5 D 2

To determine the total number of 2° amine isomers of C4H11N, we need to consider the different possible structural arrangements.

Step 1: Determine the possible structures of C4H11N. C4H11N can be represented as R-NH-R, where R represents any alkyl group. In this case, we have four carbon atoms (C4) and one nitrogen atom (N). The alkyl groups can be arranged in different ways.

Step 2: Identify the different possible arrangements. To determine the number of possible arrangements, we need to consider the different ways the alkyl groups can be attached to the nitrogen atom. Let's consider the different possibilities:

• Two alkyl groups attached to the same nitrogen atom (R-NH-R): This is known as a 2° amine. In this case, we have two possibilities: R1-NH-R2 and R2-NH-R1.

• Three alkyl groups attached to the same nitrogen atom (R-NH-R-R): This is known as a 3° amine. However, we are only interested in 2° amines, so we can exclude this possibility.

• One alkyl group attached to each nitrogen atom (R-NH2): This is known as a 1° amine. However, we are only interested in 2° amines, so we can exclude this possibility.

Step 3: Count the number of 2° amine isomers. From the possibilities identified in step 2, we have two different arrangements for 2° amines: R1-NH-R2 and R2-NH-R1. Therefore, the total number of 2° amine isomers of C4H11N is 2.

Therefore, the correct answer is D) 2.