Question

What is the chemical composition of Nicol’s prism?
A. $A{l}_2{O}_3$
B. $$CaS{O}_4$$
C. $CaC{O}_3$
D. $$N{a}_{3}Al{F}_6$$

Answer 1

Hint: Nicol prism is a polarizer which is used to form plane polarized light. The Nicol prism is typically formed of Calcite. Calcite is also the principal constituents in the formation of limestone and marble. Calcite is naturally obtained and used to form rocks.

Complete step by step answer:
A Nicol prism is a device which is used to form and analyse plane polarized light. It is typically a type of polarizer which is prepared from calcite. The calcite is a sedimentary mineral which forms rock and its chemical formula is $CaC{O}_3$. The Nicol prism is formed in such a way that it eliminates one of the total incident rays by total internal reflection. The Nicol prism was the first type of polarizing prism formed by Willliam Nicol in the year 1828.
The Nicol prism contains a rhombohedral crystal of Iceland spar which is cut by the angle of 68 degree relating to the crystal axis. Then it is cut again and rejoined with the help of a layer of transparent Canada Balsam which is used as a glue.
In Nicol prism, the unpolarized light enters to the prism from the left side of the crystal which is further split into orthogonally polarized light which is directed differently by birefringence property of the calcite.
To produce the plane polarized light and analyse two Nicol prisms are arranged.
Nicol prism is used in microscopy and polarimetry technique.
Thus, the chemical composition of Nicol prism is calcium carbonate $$CaC{O}_3$$.
Therefore, the correct option is C.

Note: Nowadays, Nicol prism is replaced by different types of polarizers like Polaroid sheet and Glan-Thompson prism. Nicol prism is based on the phenomenon of double refraction.