Question

Name the process associated with the following.
Dry ice is kept at room temperature and one atmospheric pressure.
A.Evaporation
B.Sublimation
C.Condensation
D.Liquefaction

Answer 1

Hint:Dry ice is a solid form of carbon dioxide.
It doesn't leave any residue after the conversion.
Dry ice conversion takes place at earth atmospheric pressures.

Complete step by step answer:
We will discuss each process one by one in detail.
Evaporation:
Evaporation is the process in which an element or compound transitions from its liquid state to its gaseous state. The rate of evaporation depends on the evaporating surface and the air.
Thus in the evaporation process elements change from liquid state to gaseous state. But dry ice is a solid.
Sublimation:
Sublimation is the process just like melting, freezing, and evaporation. In sublimation, a substance changes from a solid to a gas without ever passing through a liquid phase.
Thus in the sublimation process, the liquid phase is not formed, and also in dry ice, no liquid phase is formed.
So dry ice undergoes the sublimation process.
Condensation:
Condensation is the change of the physical state from the gas phase into the liquid phase and this process is the reverse of vaporization.
Thus dry ice is solid so it doesn't undergo this process.
Liquefaction:
Liquefaction is a process of conversion of the solid or gas phase into the liquid phase.
Dry ice is solid but it doesn’t convert into liquid. So this process was not taking place.
Hence, the correct option is B.


Note:
“Dry ice” is solid, frozen carbon dioxide, which happens to sublimate, to turn to gas, at a chilled temperature $ - 78.5\% $ $\left( { - 109.3^\circ F} \right)$.
The sublimation of dry ice is a physical change and not a chemical change. So carbon dioxide gas is produced.