Question

For a molecule with two like chiral carbon atoms, the number of optically inactive form is ?

• A.
  $1$
• B.
  $2$
• C.
  $3$
• D.
  $4$

Answer 1

The correct option is A

$1$
For a molecule with two like chiral carbon atoms, the number of isomers will be 3. Out of three, two are optically active and one is optically inactive due to the symmetry in the molecule. This optically inactive isomer is called mesomer.
Meso compounds are optically inactive though they have a chiral centres due to the presence of plane of symmetry or centre of symmetry.
Hence, (a) is correct.