The purpose of this lab was to have students observe a chemical reaction. An empty crucible was weighed, 1 gram of copper powder was placed in the
crucible, and the powder was heated for about 10 minutes. During heating, the powder was stirred every 2 minutes to ensure that all the
copper would undergo the reaction. Students observed the copper before and after heating, and the mass was taken after heating.
The copper should have weighed more after heating, because of the addition of oxygen according to the equation below:
2Cu + O2 --> 2CuO