Q. The use of plaster of Paris is in

1849 205 Uttarkhand PMTUttarkhand PMT 2007 Report Error

A

whitewash

B

toothpaste

C

black board chalk

D

surgery and dentistry

Solution:

Gypsum on heating loses a part of its water of crystallisation to form plaster of Paris.
$g y p s u m 2 C a S O_{4} .2 H_{2} O 12 0^{\circ} C Plaster of Paris (C a S O_{4})_{2} H_{2} O + 3 H_{2} O$
Plaster of Paris an mixing with water form gypsum and sets to hard mass with little expansion. Therefore, it is used in surgery and dentistry.