To the Viewer

This sequence of video segments was filmed during a regular SWH laboratory session. Participants are typical students and their teaching assistant.  Most excerpts represent the SWH classroom well. However, the wrap-up discussion is somewhat less spontaneous and student-driven than usual, probably due to the presence of the videographers. For most of the filming, the videographers were transparent as they moved among the students. During the discussion, the student participants appeared not to want to make an error on film. Hence, the instructor (teaching assistant) prodded them a little more than she normally would have to help them to understand that they were correctly analyzing the class data set and verbalizing an intelligent conceptual understanding of their results.

Chemistry 163L Experiment
Predicting the Results of a Chemical Reaction

You will be given:
copper wire & powdered sulfur
wire cutter
crucible and lid
spatula
ring stand
iron ring
clay triangle
Bunsen burner
crucible tongs
wire gauze

You will have access to a balance that will weigh to four places after the decimal point.

THIS REACTION MUST BE CONDUCTED IN A WELL-VENTILATED AREA. PLEASE KEEP ALL EQUIPMENT UNDER THE HOOD.

React between 15 and 25 cm of copper wire with excess sulfur in a crucible. Can you predict the results?

Form the copper into a coil that will fit into your clean, dry, pre-massed crucible. (You should weigh both the crucible and lid.)

Completely cover the copper with powdered sulfur. Describe both reactants. With the lid completely covering the crucible, heat the contents until there is no longer any sign of reaction. Do not open the lid until all visible signs of reaction cease. Why?

If there is any evidence of sulfur remaining when you open the lid to check the system, continue heating until all signs of sulfur are gone.

Describe the product. What is the mass of the product?

Completely cover the product with sulfur and again heat the contents until there is no longer any sign of reaction. Heat the crucible to constant mass.

What is the compound that is formed?