Question

The number of geometrical isomers of $CH_{3} CH=CH-CH=CH-CH=CHCl$ is

• A. 2
• B. 4
• C. 6
• D. 8

Answer 1

The Correct Option is D

To determine the number of geometrical isomers for the compound CH_{3}CH=CH-CH=CH-CH=CHCl, we need to consider the concept of geometrical (cis-trans) isomerism in alkenes.

Geometrical isomerism arises due to the restricted rotation around a double bond. Each double bond can exist in either a cis or trans configuration, giving rise to different isomers. The condition for geometrical isomerism is that each carbon atom of the double bond must have two different substituents.

Let's analyze the given compound:

1. The compound CH_{3}CH=CH-CH=CH-CH=CHCl has three double bonds.
2. Each of these double bonds has two different groups on the carbon atoms involved in each double bond. Thus, each double bond can have two configurations: cis or trans.
3. The number of geometrical isomers is calculated as 2^n, where n is the number of double bonds capable of exhibiting geometrical isomerism.
4. Here, n = 3, since all three double bonds can exhibit geometrical isomerism.

Therefore, the number of geometrical isomers for the given compound is:

2^3 = 8

Thus, the correct answer is 8.