Suggest the name of a Lewis acid other than anhydrous aluminium chloride which can be used during ethylation of benzene.

Explanation

To answer the question regarding a Lewis acid that can be used during the ethylation of benzene, we can follow these steps:

### Step 1: Understand the Ethylation of Benzene
Ethylation of benzene refers to the process of introducing an ethyl group (C2H5) into the benzene ring. This is typically achieved through an electrophilic aromatic substitution reaction, where a Lewis acid acts as a catalyst.

### Step 2: Identify Common Lewis Acids
A Lewis acid is a substance that can accept an electron pair. While anhydrous aluminium chloride (AlCl3) is a well-known Lewis acid used in this reaction, we need to suggest another one.

### Step 3: Suggest an Alternative Lewis Acid
One alternative Lewis acid that can be used for the ethylation of benzene is **Ferric Chloride (FeCl3)**. Ferric chloride is effective in generating the ethyl cation (C2H5+) from ethyl halides, facilitating the ethylation process.

### Step 4: Conclusion
Thus, the name of a Lewis acid other than anhydrous aluminium chloride that can be used during the ethylation of benzene is **Ferric Chloride (FeCl3)**.

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