Number of `pi` -bonds present in B.H.C. (Benzene hexachloride) are:

Options

A. 6
B. Zero
C. 3
D. 12

Answer

To determine the number of π-bonds present in Benzene Hexachloride (B.H.C.), we can follow these steps:

### Step 1: Understand the Structure of Benzene Hexachloride
Benzene hexachloride is derived from benzene, which has the formula C₆H₆. In benzene, each carbon atom is bonded to one hydrogen atom and forms a planar ring structure with alternating single and double bonds. However, in benzene hexachloride, all hydrogen atoms are replaced by chlorine atoms, leading to the formula C₆Cl₆.

### Step 2: Identify the Type of Bonds in Benzene
In benzene, the carbon atoms are connected by alternating single and double bonds. Each double bond consists of one σ-bond and one π-bond. The structure of benzene can be represented as follows:
- C=C (double bond) contributes 1 π-bond.
- C-C (single bond) contributes no π-bond.

### Step 3: Count the Number of π-bonds in Benzene
In the original benzene structure (C₆H₆), there are 3 double bonds. Each double bond contributes one π-bond. Therefore, in benzene, there are:
- 3 double bonds × 1 π-bond per double bond = 3 π-bonds.

### Step 4: Analyze the Effect of Chlorine Substitution
When all hydrogen atoms in benzene are replaced by chlorine atoms to form benzene hexachloride, the π-bonds remain unchanged because the substitution does not affect the π-bonds between the carbon atoms. Hence, the number of π-bonds in benzene hexachloride remains the same as in benzene.

### Step 5: Conclusion
Thus, the total number of π-bonds present in Benzene Hexachloride (B.H.C.) is 3.

### Final Answer:
The number of π-bonds present in Benzene Hexachloride (B.H.C.) is **3**.

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