Chemistry - STEREO ISOMERISM Question with Solution | TestHub

The conformers are Newman projections of 1,2-dichloroethane, ClCH₂-CH₂Cl.

(A) The anti conformer : the plane containing Cl-C-C-Cl bisects the H-C-H angles on both carbons, so a plane of symmetry is present.

(B) The gauche conformer : no symmetry element relating the two ends - no plane.

(C) The eclipsed conformer with Cl eclipsing H : the two ends carry different eclipsing pairs, so no plane.

(D) The fully eclipsed conformer with Cl eclipsing Cl : the plane containing both Cl-C-C-Cl bonds and bisecting the H-C-H angles is a plane of symmetry.

Ans. (A, D)