Question

Calculate the total number of optical isomers of the following compounds respectively :

Tartaric acid, lactic acid, fumaric acid and cinnamic acid.

• A. $3,2,0,2$
• B. $3,2,0,1$
• C. $2,2,0,0$
• D. $3,2,0,0$

Answer 1

The correct option is D $3,2,0,0$

Fumaric acid and cinnamic acid doesn't have chiral carbon so they have zero optical isomers.
Lactic acid is chiral and has two optical isomers. One is known as L-(+)-lactic acid or (S)-lactic acid .
Tartaric acid has 3 optical isomers (two are enantiomers and one is meso-compound).