What is meant by racemic mixture ?

Explanation

### Step-by-Step Solution

1. **Definition of Racemic Mixture**: A racemic mixture is defined as a mixture that contains equal amounts of two enantiomers. Enantiomers are molecules that are mirror images of each other and cannot be superimposed.

2. **Understanding Enantiomers**: There are two types of enantiomers based on their optical activity:
- **Dextrorotatory (d)**: This type of enantiomer rotates plane-polarized light to the right (clockwise). It is denoted by the symbol (+) or d.
- **Levorotatory (l)**: This type of enantiomer rotates plane-polarized light to the left (counterclockwise). It is denoted by the symbol (−) or l.

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