Lab - Properties of Ionic Compounds
Name____________________
Background: In this investigation, you will test various compounds for their melting
point, odor, and conductivity. Some of the compounds are ionic and some of them are
not. Your task is to identify the ionic compounds and to note the properties that they
share.
Procedure:
Melting point: To test the melting point, place a small amount of the compound into a
deflagration spoon and place it in the hottest part of your Bunsen burner flame. If the
compound melts instantly, record the melting point as "low". If it doesn't melt easily,
record "high" for the melting point. Remove as soon as melting occurs.
Odor: Smell the compound from the chemical containers. Describe the odor as either
"odor" or "odorless" in the data table.
Conductivity: Submerge the electrodes in the prepared solution of the compound and
identify it as an "electrolyte” or a "non-electrolyte". Be sure to rinse the electrodes with
water after each trial.
Data:
Compound Melting Point
Formula (High or Low)
CaCl2
Na2CO3
C6H4Cl2
C10H8
K2CrO4
C7H6O2
Odor or
Odorless?
Conductivity (Electrolyte
or Non-Electrolyte)
Analysis/Conclusions:
1. Look at all three properties for each compound and form two groups of three based on the similarity
of their properties. Write just the chemical formulas for your groupings.
Group 1:
Group 2:
2. Are the compounds in group 1 made up of metals, nonmetals, or a combination of both?
3. Are the compounds in group 2 made up of metals, nonmetals, or a combination of both?
4. Which group represents compounds that are ionic (see section 7.2 of your text)? Explain.
5. Circle the words in parentheses that make the statement correct. From the data, we can generalize
that ionic compounds have (high, low) melting points, have (a distinct odor, no odor), and are
(electrolytes, non-electrolytes) when dissolved in water.
6. Both melting point and odor are directly related to bond strength. Do you think ionic compounds
contain bonds that are strong or weak? Explain. Hint: Think about what has to happen at a molecular
level in order to melt a solid and be able to smell a compound.
7. Hardness is also directly related to bond strength. Would you expect ionic compounds to be hard or
soft? Explain.
8. Predict the properties of the compounds in the table based on the results of this lab.
Compound
Formula
MgO
C8H18
Ba(OH)2
Melting Point
(High or Low)
Odor (Strong
or None)
Conductivity (Electrolyte
or Non-Electrolyte)