Name the catalyst used in Friedel-Crafts reactions,

Explanation

**Step-by-Step Solution:**

1. **Understanding Friedel-Crafts Reactions**: The Friedel-Crafts reactions are important types of electrophilic aromatic substitution reactions. There are two main types: Friedel-Crafts alkylation and Friedel-Crafts acylation.

2. **Identifying the Catalyst**: Both types of Friedel-Crafts reactions require a catalyst to facilitate the reaction. The catalyst used in these reactions is anhydrous aluminum chloride (AlCl3).

3. **Role of the Catalyst**: Anhydrous AlCl3 acts as a Lewis acid. It accepts an electron pair, which helps in generating the electrophile necessary for the reaction.

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