Chapter U1.7, Problem 2E

Interpretation Introduction

Interpretation:

The possibility for presence of copper in starting as well as end of a series of chemical reactions needs to be explained.

Concept introduction:

Chemistry deals with the different processes which occur in surrounding and is directly or indirectly related with each other.

Different changes taking place in the environment can be physical and chemical on the basis of change in physical state and chemical composition of the matter.

Physical changes are related to change in the physical state of the substance whereas the chemical change is associated with change in chemical composition that results the formation of new chemical substance/s.

Answer to Problem 2E

It is possible to start with copper and end up with copper after a series of chemical reactions as in each step of the reaction series, the substance copper remains because all chemical reactions follow the Law of conservation of mass.

Explanation of Solution

All chemical reaction follows the Law of Conservation of Mass. It states that the mass of matter remains the same and it only converts from one form to another. In each step of the reaction series, the substance copper remains same although forms changes after different processes like heating or mixing. But the element Cu remains same in all steps. Thus, it is possible to start with copper and end up with copper after a series of chemical reactions.

Conclusion

According to the Law of Conservation of Mass, “mass cannot be created or destroyed.”