Question

Label each compound as chiral or achiral.

a.

b.

c.

d.

Short answer

1. Achiral.
2. Chiral.
3. Achiral.
4. Chiral.

Step-by-step solution

Meaning of chiral and achiral compounds

A molecule is classified as a chiral molecule if the mirror image of that molecule is not superimposable. The chiral molecule has two different stereoisomers, and these are known as enantiomers.

Achiral molecules are those molecules that have superimposable mirror images. The achiral molecules have a plane of symmetry or center of symmetry. The molecule having at least one stereogenic center is always chiral.

Identification of chiral and achiral compounds

The chiral and the achiral compounds can be identified by using the mirror plane. The structure of the molecule is drawn, and then the reflection of the structure is drawn. The molecule whose mirror image is superimposable is chiral.

a. The mirror image of the given compound is shown below:

Achiral molecule

The mirror image of the above molecule is superimposable. Hence, the above molecule is achiral.

b. The mirror image of the given compound is shown below:

Chiral molecule

This molecule is chiral because its mirror image is non-superimposable.

c. The mirror image of the given compound is as shown below:

Achiral molecule

The above molecule is also achiral in nature due to the superimposable mirror image.

d. The mirror image of the compound is as follows:

This molecule has a non-superimposable mirror image. It is chiral in nature.