Which one of the following is racemic compound? ans. meso-tartaric acid d,l-tartaric acid acetic acid (-) mandelic acid

The racemic compound among the given options is d,l-tartaric acid.

A racemic compound is a mixture of equal amounts of two enantiomers, meaning it has no net optical activity. In the case of tartaric acid, the d,l- form is a racemic mixture because it contains equal amounts of the dextro (d-) and levo (l-) forms of the molecule.

Meso-tartaric acid, on the other hand, is not optically active because it has an internal plane of symmetry. Acetic acid and (-) mandelic acid are not racemic because they do not consist of a 1:1 mixture of enantiomers.