In presence of UV light, benzene reacts with chlorine forming _________

Answer

To solve the question "In presence of UV light, benzene reacts with chlorine forming _________", we can follow these steps:

### Step 1: Understand the Reactants
Benzene is a cyclic hydrocarbon with the formula C6H6. It consists of six carbon atoms arranged in a ring, with alternating double bonds. Chlorine (Cl2) is a diatomic molecule that can react with other substances.

**Hint:** Identify the structure and formula of benzene and chlorine before proceeding.

### Step 2: Identify the Reaction Conditions
The reaction occurs in the presence of UV light. UV light provides the energy needed to initiate the reaction, breaking the Cl-Cl bond in the chlorine molecule, leading to the formation of chlorine radicals.

**Hint:** Remember that UV light is crucial for initiating free radical reactions.

### Step 3: Describe the Reaction Mechanism
When benzene reacts with chlorine under UV light, a substitution reaction occurs. The chlorine radical generated from the dissociation of Cl2 will react with benzene, replacing one of its hydrogen atoms. This process can continue, leading to further substitution until all hydrogen atoms are replaced.

**Hint:** Consider the nature of substitution reactions in aromatic compounds.

### Step 4: Determine the Product
The final product of this reaction is hexachlorobenzene, which has the chemical formula C6Cl6. It is formed when all six hydrogen atoms in benzene are replaced by chlorine atoms.

**Hint:** Recall the naming conventions for organic compounds to identify the product correctly.

### Step 5: Common Name of the Product
Hexachlorobenzene is commonly known as "Gammexane." It is important to note that this compound has applications as a pesticide.

**Hint:** Familiarize yourself with common names of chemical compounds, as they can differ from IUPAC names.

### Final Answer
In the presence of UV light, benzene reacts with chlorine to form **hexachlorobenzene**, commonly known as **Gammexane**.

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