Chapter 17, Problem 12RQ

To determine

The difficulty to decide whether an observed change is physical or chemical.

Answer to Problem 12RQ

It is sometime difficult to decide whether an observed change is physical or chemical because in both the physical as well as chemical changes, the physical appearances are changed.

Explanation of Solution

A physical change in a chemical reaction contributes to the change in colour, state, density, etc. of a reactant and product species. Whereas, a chemical change in a chemical reaction states about the change in their chemical nature, properties, reactivity, etc.

As in both the changes during a chemical reaction, there is something getting changed and thus it is difficult to identify the change taking place in a chemical reaction.

Thus, it is difficult to predict whether a change occurring is a physical or a chemical change as in both chemical changes, the physical nature are disturbed.

Conclusion:

Therefore, it is sometime difficult to decide whether an observed change is physical or chemical because in both the physical as well as chemical changes, the physical appearances are changed