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) Ci (Center of symmetry) is present |
(D) | (S) Plane of symmetry is present |
Options:
Answer:
Solution:
Ans. A P, R, S; B Q, S; C P, Q, R, S; D P, R, S.
A (1,4-dimethyl-2,5-dichlorobenzene): C2 axes pass through the ring, the ring centre is a centre of symmetry (CH3 mapping onto CH3 and Cl onto Cl) and the molecular plane is a mirror plane : P, R, S.
B (triphenylene, D3h): a C3 axis perpendicular to the molecular plane and mirror planes, but no centre of symmetry (D3h has σh, not i) : Q, S.
C (benzene, D6h): C2, C3 and C6 axes, a centre of symmetry and mirror planes : P, Q, R, S.
D (p-dichlorobenzene, D2h): C2 axes, a centre of symmetry at the ring centre and mirror planes, but no C3 axis : P, R, S.
