Cyclisation of n-heptane will give

Options

A. toluene
B. naphthalene
C. benzene
D. all the above

Explanation

To solve the question regarding the cyclization of n-heptane, we will follow these steps:

### Step 1: Understand the structure of n-heptane
n-Heptane is a straight-chain alkane with the molecular formula C7H16. Its structure can be represented as:
\[ \text{CH}_3 - \text{CH}_2 - \text{CH}_2 - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]

### Step 2: Identify the cyclization process
Cyclization refers to the process of converting a linear chain hydrocarbon into a cyclic structure. In the case of n-heptane, when subjected to specific conditions, it can undergo cyclization.

### Step 3: Conditions for cyclization
The cyclization of n-heptane typically requires:
- A catalyst (e.g., platinum on alumina)
- High temperature (around 600°C)
- High pressure (approximately 10 atmospheres)

### Step 4: Determine the product of cyclization
When n-heptane is treated under these conditions, it can lose hydrogen atoms and rearrange to form a cyclic compound. The most likely product from the cyclization of n-heptane is toluene (C7H8), which has a benzene ring with a methyl group attached.

### Step 5: Analyze the options
The options given are:
1. Toluene
2. Naphthalene
3. Benzene
4. All of the above

Since the primary product from the cyclization of n-heptane is toluene, we can conclude that:

### Final Answer
The correct answer is **Option 1: Toluene**.

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