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

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

Here's why:

1. A racemic compound is a mixture of equal amounts of two enantiomers, which means it has no net optical activity.

2. Meso-tartaric acid is not a racemic compound because it is achiral, meaning it has a plane of symmetry.

3. Acetic acid is not a racemic compound because it does not have a chiral center, so it does not have enantiomers.

4. (-) mandelic acid is not a racemic compound because it is a single enantiomer, not a mixture of enantiomers.

5. d,l-tartaric acid, however, is a racemic compound because it is a 1:1 mixture of d-tartaric acid and l-tartaric acid, which are enantiomers of each other.