The number of structural isomers of C4H9Cl is - 2 - 3 - 4 - 5 - VCE - SSCE Chemistry - Question 2 - 2012 - Paper 1

To identify the structural isomers, we can consider various arrangements of the carbon skeleton and the position of the chlorine substituent:

1. Straight Chain Isomers: The main carbon chain can be straight (butane).
2. Branched Isomers: The carbon chain can be branched, leading to different configurations (e.g., isobutane).
3. Position Isomers: Chlorine can be attached to different carbons creating new isomers.

After analyzing the arrangements, we find the following structural isomers for C4H9Cl:

1. 1-chlorobutane: Chlorine on the terminal carbon.
2. 2-chlorobutane: Chlorine on the second carbon.
3. 1-chloro-2-methylpropane: Chlorine on the terminal carbon of a branched chain.
4. 2-chloro-2-methylpropane: Chlorine attached to the central carbon of a branched chain.

Thus, there are a total of 4 structural isomers.

The total number of structural isomers for C4H9Cl is 4. Therefore, the correct answer is C.