Chapter 3, Problem 16STP

Interpretation Introduction

Interpretation:

Difference between a chemical change and a physical change. Whether the combination of gasoline a chemical change or a physical change or not.

Concept introduction:

The chemical change, in which, the new product is formed and the absorption of energy or the loss of energies are in a different form.

A physical change is defined when the composition of substance does not change. Only state transfer takes place in the physical change.

Answer to Problem 16STP

When any change in reaction does not modify the composition of any substance, called physical change.

Chemical change is defined as a change where one or more than two substances are changed into other new substances.

The combustion of gasoline is categorized in a chemical change. In this process, gasoline is changed into other substances throughout combustion.

Explanation of Solution

The difference between a physical and a chemical change are mentioned below:

Physical change	Chemical change
In the physical changes, the change is for a short duration.	These changes are permanent.
There is very little quantity in were absorption of the heat.	In chemical changes absorption and loss of energy take place.
The physical changes, there is only phase transfer take place.	The chemical changes are irreversible.
In the physical changes, no production of energy takes place.	In the chemical changes, the energy produces in the form of light, heat, etc.

The combustion process is a chemical change because, in this process, a new product is formed. Also, the evolution of gases and energy loss takes place. In the combustion process of gasoline, water is formed as a new product and carbon dioxide gas releases.

Conclusion

Chemical change and physical change describe the different nature of substances. The combustion process is a chemical change because, in this process, a new product is formed which is different from an original product.