Ionic and Covalent Compounds

Lab: Ionic and Covalent Compounds

1. List the properties of ionic compounds.
- Solids at room temperature.
- Soluble in water.
- Conduct electricity (while in solution).
- Very high melting and boiling points.
2. List the properties of covalent compounds.
- Solids, liquids, or gases at room temperature.
- May or may not be soluble in water.
- Most do not conduct electricity (except for acids)
- Low melting and boiling points.
3. Give the name and formula for:
a) 3 ionic compounds
NaCl—Sodium Chloride
FeCl3—Iron (III) Chloride
MgO—Magnesium Oxide
b) 3 covalent compounds
NO—Nitrogen Monoxide
CBr4—Carbon Tetrabromide
N2O5—Dinitrogen Pentoxide

Laboratory Procedure
Testing eight different substances by doing one or more of the following:
a) Putting the substances in water to test its solubility.
b) Testing conductivity by using an ‘electric apparatus’.
c) Conducting a flame test by using a little bit of the solution and exposing it to an open flame.

In experiment ‘a’, we used a 50 ml beaker and added approximately 10 to 20 ml of water to it. Then we took a small sample of the unknown substance and put it into the beaker. If it dissolved, it was obviously soluble in water. If the substance remained in it’s original physical state, it wasn’t.

In experiment ‘b’, we used the same beaker and substance left over from experiment ‘a’ to test its conductivity. We took the substance to the electrical apparatus used to test for conductivity; if the light-bulb lit up, the substance is conductive, if it stayed off, then the substance is not conductive.

In part ‘c’ of the experiment, we conducted a flame test. This was only necessary as a last resort of we couldn’t tell the substances apart based on the solubility and conductivity tests. In this part, we took a small sample of the substance and put it on the very edge of a scoopula. Depending upon the color of the flame when the substance was put into it determined which substance it was.

Post-Lab Questions

1. What did you notice when it came to determining the conductivity of ionic compounds versus the conductivity of covalent compounds?
I noticed that all the ionic compounds conduct electricity, whereas the covalent compounds do not.

2. What did you notice when it came to determine the solubility of ionic compounds versus the solubility of covalent compounds?
A majority of the solutions were soluble in water, however, the two that were not were covalent compounds.

3. What did you notice about the differences in melting points and boiling points when it came to the covalent verses the ionic compounds.
The ionic compounds seem to have relatively high melting and boiling points, whereas the covalent compounds have relatively small melting and boiling points, compared to the ionic substances