Question

Potassium chlorate decomposes to potassium chloride and oxygen gas. Is this a physical or chemical change?

Answer 1

This process is clearly an example of chemical change.

Explanation:

Chemical change is characterized by the formation of new substances, and the making and breaking of strong chemical bonds.

Here, we have the reaction:

`KClO_3(s) + Delta rarr KCl(s) + 3/2O_2(g)uarr`

This reaction works best with a little `MnO_2` catalyst. Clearly, strong chemical bonds have been broken, and reformed in new substances.