Chemistry - STEREO ISOMERISM Question with Solution | TestHub
Match the following :
Column-I | Column-II |
|---|---|
(A) | (P) C2-axis of symmetry is present |
(B) | (Q) C3-axis of symmetry is present |
(C) | (R) Plane of symmetry is present |
(D) | (S) Center of symmetry is present |
| (T) S4 alternative axis of symmetry |
Options:
Answer:
Solution:
Ans. A P, R, S; B P, Q, R, S; C P, R, T; D P, R.
A (trans-1,2-dibromoethene, C2h): a C2 axis perpendicular to the molecular plane, mirror planes and a centre of symmetry at the midpoint of C=C : P, R, S.
B (benzene, D6h): C2 and C3 axes, mirror planes and a centre of symmetry : P, Q, R, S. (Its principal axis is C6; no S4.)
C (allene, H2C=C=CH2, D2d): C2 axes, two σd planes and an S4 alternating axis along the C=C=C chain, but no centre of symmetry and no C3 : P, R, T.
D (cis-1,2-dichloroethene, C2v): a C2 axis and two mirror planes, no centre of symmetry : P, R.
