Question

which of the following statements is true about the molecules shown below?
select the correct answer below:
both are chiral.
both are achiral.
the first molecule (a) is chiral, and the second molecule (b) is achiral.
they are stereoisomers.

Explanation:

Step1: Determine chirality of molecule (a)

A chiral carbon has four different groups. In molecule (a), the central carbon has \(H\), \(CH_3\), \(Cl\), \(Br\) (four different groups). So, it is chiral.

Step2: Determine chirality of molecule (b)

In molecule (b), the central carbon has \(H\), \(CH_3\), \(H\), \(Br\) (two \(H\) groups - not four different). So, it is achiral.

Step3: Check stereoisomer option

Stereoisomers have same connectivity but different spatial arrangement. Molecule (a) has four different groups, molecule (b) has two same groups. They are not stereoisomers.

Answer:

The first molecule (a) is chiral, and the second molecule (b) is achiral.