Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) Nicol prism | (I) Spatial arrangement of functional groups around a carbon atom |
| (B) Polarimeter | (II) Measures the angle by which plane polarised light is rotated |
| (C) Configuration | (III) Produces plane polarised light from ordinary light |
| (D) Asymmetric carbon (stereocentre) | (IV) A carbon atom to which four different groups are attached |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-III, B-II, C-I, D-IV
Optical activity is the rotation of the plane of plane polarised light by the solution of a compound. Two devices are used to study it, and two terms describe the structure behind it.
(A) Nicol prism — This matches (III) Produces plane polarised light from ordinary light. Ordinary light passed through a Nicol prism comes out plane polarised; this light is then passed through the solution.
(B) Polarimeter — This matches (II) Measures the angle by which plane polarised light is rotated. The polarimeter shows the angle of rotation, and whether it is to the right (+) or to the left (–).
(C) Configuration — This matches (I) Spatial arrangement of functional groups around a carbon atom. Two structures of the same compound that are mirror images differ in their configuration.
(D) Asymmetric carbon (stereocentre) — This matches (IV) A carbon atom to which four different groups are attached. With four different groups around a tetrahedral carbon, the mirror image of the molecule cannot be superimposed on it.
NCERT (2026-27 edition):
6.7.1 Reactions of Haloalkanes – “(i) Optical activity: Plane of plane polarised light produced by passing ordinary light through Nicol prism is rotated when it is passed through the solutions of certain compounds. Such compounds are called optically active compounds. The angle by which the plane polarised light is rotated is measured by an instrument called polarimeter.”
“Spacial arrangement of functional groups around carbon is called its configuration.”
“…the spatial arrangement of four groups (valencies) around a central carbon is tetrahedral and if all the substituents attached to that carbon are different, the mirror image of the molecule is not superimposed (overlapped) on the molecule; such a carbon is called asymmetric carbon or stereocentre.”