Chapter 12, Problem 75A

Interpretation Introduction

Interpretation:

The difference between sublimation and deposition needs to be explained.

Concept introduction:

There are three states of matter namely solid, liquid and gas. One phase of a matter can be converted into other involving heat. In some conversions, heat is absorbed and in some heat is released.

If matter with strong intermolecular forces is converted into one with weak intermolecular forces, heat is absorbed in the transition and if matter with weak intermolecular forces is converted into one with strong intermolecular forces, heat is released in the transition.

The intermolecular forces in solid is strongest followed by liquid and gas.

Explanation of Solution

In the process of sublimation, a solid material gets converted into gas without forming liquid. Similarly, in deposition process, a gas is converted directly to a solid. Thus, the difference between two is based in the transition taking place in these transitions.

Thus, solid to gas is sublimation and gas to solid is deposition.

In the conversion of solid to gas, large amount of heat is required thus, the process is endothermic. The conversion of gas to solid, heat is released thus, it is an exothermic reaction.