Q. Dry ice is
A) Solid $H_{2}O$
B) Solid $CO_{2}$
C) Solid $N_{2}O_{4}$
D) Solid $NH_{3}$
Explanation
(b)
Solid $CO_{2}$ sublimes directly to the vapour state (without converting into liquid) at $- 78℃$ under atmospheric pressure, hence used as a refrigerant and called dry ice or cardice. It is used to freeze metals, ice-cream and in laboratory as a coolant.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.