Chapter 3, Problem 45A

Interpretation Introduction

Interpretation:

Whether change in phase is a physical or a chemical change needs to be determined.

Concept introduction:

The nature of any substance is explained by their chemical properties and physical properties.

A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc.

A chemical property describes how a substance reacts with other substances. In a chemical change, a new substance is formed and absorption of energy or loss of energy occurs; it is an irreversible change. For example, rusting, dissolving, etc.

Answer to Problem 45A

The change in the phase is physical.

Explanation of Solution

In the process of phase transfer, no new substance will be formed and also, this change is reversible. Freezing of ice from water is a phase transfer. There is a change in the position of the water molecules due to decrease in the energy, but the composition of ice and water remains the same.

Conclusion

The change is a physical change.