Question

Which isomeric form of benzene hexachloride is used as insecticide?

• A. $\alpha$-form
• B. $\beta$-form
• C. $\gamma$-form
• D. $\delta$-form

Hint:

Remember: $\gamma$-BHC = Lindane = insecticide (very common exam question).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Benzene hexachloride (BHC), also known as 1,2,3,4,5,6-hexachlorocyclohexane, exists in several stereoisomeric forms. Some of these isomers have different biological activities.
Step 2: Detailed Explanation:
BHC is produced by the addition of chlorine to benzene in the presence of sunlight.
The resulting mixture contains several isomers (\( \alpha, \beta, \gamma, \delta, \epsilon \)).
Among these, the \( \gamma \)-isomer (gamma-BHC) is the only one with powerful insecticidal properties.
It is commonly sold under the trade names Gammexane, Lindane, or 666.
Step 3: Final Answer:
The \( \gamma \)-form of benzene hexachloride is used as an insecticide.