What are enantiomers

Answer

**Step-by-Step Text Solution:**

1. **Definition of Enantiomers**: Enantiomers are a specific type of stereoisomer. They are defined as chemical isomers that are non-superimposable mirror images of each other. This means that if you were to place one enantiomer over the other, they would not align perfectly, much like how your left and right hands are mirror images but cannot be perfectly aligned on top of each other.

2. **Characteristics of Enantiomers**: Enantiomers have identical physical properties such as boiling point, melting point, and density, but they differ in their optical activity. This means that they rotate plane-polarized light in opposite directions; one enantiomer will rotate light to the right (dextrorotatory) and the other to the left (levorotatory).

3. **Example of Enantiomers**: A common example of a pair of enantiomers is lactic acid. There are two forms: dextrolactic acid (often referred to as D-lactic acid) and levolactic acid (L-lactic acid). The chemical structure of lactic acid can be represented as C3H6O3, and its two enantiomers have the same molecular formula but differ in the arrangement of atoms around a chiral center.

4. **Visual Representation**: To visualize enantiomers, one can draw the structure of lactic acid and its mirror image. The structural formula of dextrolactic acid can be represented as CH3-CHOH-COOH, while its mirror image, levolactic acid, would be the same formula but arranged differently around the chiral center.

5. **Importance of Enantiomers**: Enantiomers are significant in the field of pharmaceuticals because they can have very different biological activities. One enantiomer may be therapeutically beneficial, while the other may be inactive or even harmful.