Conductivity and Bonding

Summary

Students will measure the conductivity of several compounds and solutions in order to predict the bond types (ionic or covalent) in the substances tested.

Materials

• student sheet (attached)
• goggles
• conductivity apparatus (conductivity indicator)
• chemplates with large enough wells for both probes to fit in solution
• hot plate (demo)
• evaporating dish (demo)
• containers of NaCl, Sucrose, KCl, and KClO3 for teacher only if doing demo.

Student Prior Knowledge

Students should know that electrical currents are produced and measured by the movement of positive or negative particles; and that in solids only negative charges (free electrons) can move.

Instructional Procedures

Teacher's demos: (optional)

KClO3 can explode or ignite if it is heated to decomposition or mixed with acids or organic matter. Heat it just unitil it melts, use it behind a demonstration shield or a hood.

Molten: Place about 3 g of the solid in an evaporating dish and heat to melting with a burner.

If you don't want to demo these then just delete them from the data table.

This lab works best in the dark--you can see the light bulb better

Note: Additional compounds may be used, of course.

Directions for student lab are detailed on the student worksheet attached.

Bibliography

Lesson Design by Jordan School District Teachers and Staff.