Procedure:

1.   Mass a dry crucible

  1. Add about 1 g of copper dust.
  1. Mass the crucible and the copper dust.
  1. Heat the copper, as shown in figure 6.5 for 2 minutes.   Watch the copper carefully, making observations.

  • Does a reaction take place?

  1. When the crucible is cool, mass the crucible and its contents.

  • Did the crucible and its contents gain or lose mass?
  • Is your answer to the previous question evidence that a reaction has taken place?
  • What do you predict will happen if you continue to heat the crucible for an additional 10 to 15 minutes?

  1. Try it.
  1. Break up the contents of the crucible with a scoopula and examine the pieces.

  • Do you think that all the copper has reacted?  If not, what fraction do you estimate did not react?

NOTE: DO NOT DISCARD THE BLACK SOLID IN YOUR CRUCIBLE.  POUR THE PIECES OF SOLID INTO A TEST TUBE AND SAVE THEM FOR USE IN THE NEXT EXPERIMENT.