question_answer

Which of the following molecules is expected to rotate the plane of plane-polarised light?       AIEEE  Solved  Paper-2007

A)  

B)

C)  

D)  

Correct Answer: B

Solution :

A molecule is optically active if it contains chiral Centre and does not have plane of symmetry. So, check chiral centre and plane of symmetry in molecules. The molecule, which is optically active, has chiral centre, is expected to rotate the plane of polarised light. One chiral centre \[{{C}_{p}}-{{C}_{v}}=R/14\]optically active Two chiral centres, but plane of symmetry within molecule\[{{C}_{p}}-{{C}_{y}}=R\]optically inactive