Rubric Comparing Properties of Ionic and Covalent Compounds
18 points total
Title-.5 pt
Date-.5 pt
Prelab:
3 pts- Background: 3 points for completing the table. Title is .5 pts. A blank square is -.5 pt.
In this lab, you will make observations of several compounds to determine if the compound is
ionic (ionically bonded) or molecular (covalently bonded).
Construct a data table to compare the properties of ionic and molecular compounds. Include:
appearance, bond type, melting and boiling temperatures, conductivity, solubility, and any
other property you can find to compare.
1 pt-Equipment: What does the conductivity apparatus test for? How does it work?
-.5 pt for the purpose of the conductivity apparatus and .5 pt for how it functions.
-cleanse the electrodes with DI water after each run
1 pt-Safety: What safety precautions should you take when using the conductivity tester?
-Wearing goggles
-Don’t touch the electrodes
1 pt-Problem statement: To classify compounds as ionic or molecular (covalent) by……
-.5 pt for analyzing the solid appearance of the compounds
-.5 pt for testing the conductivity of the compound in solution.
.5 pt-Materials:
-.5 pts for conductivity apparatus, compounds in solid form, compounds in solution, DI
water, petri dish.
.5 pt Procedural changes
Procedure: WEAR GOGGLES!
1) Observe the solid compounds and the aqueous solutions. Record your observations.
2) Test the conductivity of each compound. Follow safety instructions. Record observations of
the relative brightness of the light bulb.
3) Classify each substance as strong, weak or non-electrolyte.
4) Based on all you observations, classify each compound as ionic or molecular.
3 pts-Data Collection:
Record observations in data tables. Title is .5 pts. Neatness .5pt Data table must include
observations about the solid appearance (1pt) as well as the electrolytic properties (1 pt) of the
six compounds
3 pt-Data Processing:
Classify the substances using a data table(s).
.5 pt for title .5 neatness
1 pt for classifying each as strong, weak or non electrolyte.
1 pt for classifying each as ionic or molecular.
3 pt-Results:
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Summarize your problem statement. How did you determine if a compound was ionic or
molecular? (1 pt)
Trends-what characteristics do ionic compounds have in common? What do molecular
compounds have in common? (1 pt)
For each compound, classify each compound as ionic or molecular and summarize the
appearance of each as a solid. (1 pt)
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3 pt- Conclusion
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
What kind of error did you encounter? (Think about Sample #4 and acids). In other
words, what didn't fit the pattern we established for ionic and covalent compounds? (1
pt)
What makes ionic compounds conduct a current? (1 pt)
Why are most molecular compounds non-electrolytes? (1 pt)