Chapter U5.12, Problem 2E

Interpretation Introduction

Interpretation: The reason due to which there is no need to keep sparking a fire once it is started is to be explained.

Concept introduction: Exothermic reaction is the reaction in which a lot of heat is released and energy in this reaction is expressed as negative value. In exothermic reaction, some of potential energy converted to kinetic energy.

Answer to Problem 2E

There is no need to keep sparking a fire once it is started because it is an exothermic reaction.

Explanation of Solution

The potential energy between product and reactant is the activation energy. Energy must be supplied to overcome this energy barrier. So, reactions often need a spark to get started. Once an exothermic reaction starts, the reaction itself provides necessary energy for reaction of molecules. Therefore, only single spark is needed to burn the entire forest.

Conclusion

An exothermic reaction needs only one spark.