Which of the following acids does not exhibit optical isomerism?

Options

A. Maleic acid
B. `alpha`-aminoacids
C. Lactic acid
D. Tartaric acid

Answer

A

Explanation

The necessary and essntial condition for any compound to be optically active us chirally, i.e.., the mocleule of the compound should be nonsuperposable on its mirror image. This happens whne the molcules possesses no symmetry element.
If the molecule of a compound has just one chiral acarbon, it is always optically active. maleic acid

does not exhibit optical isomerism as there is no chiral carbon (i.e. carbon bonded to four different atoms or groups of atoms). all other compounds have chiral carbons `(**)`
`underset("alpha-aminoacid")(R-overset(H)overset(|**)underset(NH_(2))underset(|)C-CO_(2)H), underset("Lactic acid")(H_(3)C-overset(H)overset(|**)underset(OH)underset(|)C-CO_(2)H), H-overset(CO_(2)H)overset(|**)overset(H-C-OH)overset(|**)underset("Tartacid acid")underset(CO_(2))underset(|)C-OH`
Note that `alpha` -aminoacid is chiral if `R = H`.