Chemistry - STEREO ISOMERISM Question with Solution | TestHub

meso-Tartaric acid has a plane of symmetry (σ) passing through the midpoint of the C₂-C₃ bond, shown by the dashed line in the Fischer projection: the upper half (C₂ with H, OH, COOH) is the mirror image of the lower half (C₃). In the Newman projection along C₂-C₃ the same plane contains the two COOH groups and the C₂-C₃ bond and reflects H into H and OH into OH. The molecule is therefore achiral (optically inactive) even though it has two stereocentres.