Question

If you heat a piece of copper, it combines with oxygen from the air to form a black layer of

copper oxide

A) Write a word equation for this reaction

B) How would the mass of your piece of copper change as you heated it?

C) Why would this happen?

Answer 1

A. When a piece of copper is heated, it combines with oxygen to form copper oxide. The chemical reaction for the same is as follows:

2 Cu (s) + O2(g) => 2CuO

B. The mass of the piece of copper will remain same and there will be no change in its mass. However, its volume will increase, so its density will decrease.

C. This is so because heating copper in its elemental form is a physical change and there is no change in mass during a physical change. Hence, the mass of copper remain same.