I always have a confusion in integer type questions which ask the nopossible isomers givig different conditions.

I dont get to know when to also include optical isomerism in the number and when not

Pla help

Dear student,

Optical isomers are molecules that differ three-dimensionally by the placement of substituents around one or more atoms in a molecule. Optical isomers were given their name because they were first able to be distinguished by how they rotated plane-polarized light. These molecules are not necessarily locked into their positions, but cannot be converted into one another, even by a rotation around a single bond.

For example, consider the following two molecules.