Chapter U5.107, Problem 1TAI

Interpretation Introduction

Interpretation: The use of a chemical reaction to do work needs to be explained.

Concept introduction: Machines are all around us doing work for us. They transport us from place to place, helps us to manufacture products, allow us to listen to music, washing our clothes, watch television etc. The source of energy for most of the machines is chemical change.

Answer to Problem 1TAI

In chemical reactions, heat transferred $q$ is used to do work.

Explanation of Solution

Work is force acting upon an object causing it to move in the direction of force. So, work is energy in motion. The heat transferred, $q$ , from chemical reactions can be used to do work. The work done by expanding gases is called $PV$ work. The combustion of fuels is one of the most common ways to transform chemical energy into work. However, some energy is also lost, due to entropy.

Conclusion

Chemical reactions are source of energy.