Chapter U4.70, Problem 3E

Interpretation Introduction

Interpretation:The five examples of physical change needs to determined and explained.

Concept Introduction: The change that affects only the form of a chemical substance but the chemical composition remains same is same said to be physical change.

Explanation of Solution

The five examples of physical changes are:

1. Melting of an ice cube:

It is a physical change in which the state of matter changes from solid to liquid and the composition of substance remains same that is ${\text{H}}_{\text{2}}\text{O}$ .

2. Dissolving sugar in water:

It is a physical change as the solid sugar molecules are separated by water and water never loses its properties as it can be recovered via evaporation of water.

3. Evaporation of rubbing alcohol:

When left uncovered, the rubbing alcohol evaporates quickly into the air that is it changes its state from liquid to gas but composition of alcohol remains same.

4. Boiling of water:

It is a physical change in which the state of matter changes from liquid to gas and the composition of substance remains same that is ${\text{H}}_{\text{2}}\text{O}$ .

5. Melting of wax:

It is a physical change in which the state of matter changes from solid to liquid and the composition of substance remains same.