CHE 11
Bonding Unit Test Review
1. Describe what happens when ionic bonds form between calcium and chlorine. Show the
electron transfer with dot diagrams, the resulting ions, and the chemical formula.
2. What does the formula K2S tell you about a crystal of potassium sulfide?
3. Explain why units of an ionic compound should not be called molecules.
4. Distinguish between an ionic bond and a covalent bond.
5. Explain how you can predict whether a compound is ionic or molecular by looking at its
chemical formula.
6. Draw Lewis structures to represent each covalent compound:
a. SiO2 b. OBr2
c. ClF
d. NF3
7. Which elements exist as diatomics in their pure form?
8. Calculate EN for bonds between the following pairs, and classify the bond type.
For polar bonds, draw arrows to indicate the direction of polarity.
a. sodium and oxygen b. nitrogen and oxygen
c. carbon and fluorine
9. What is the difference between an ionic bond and a polar covalent bond.
10. List three properties of ionic and molecular compounds that differ. Explain how they differ.
11. Use VSEPR theory to predict the shape of the following:
a. CO2
b. COH2
c. SF2
12. Determine whether each molecule in #11 is polar or nonpolar. Indicate the direction of
polarity for all polar molecules.
13. Explain why the boiling point of a pure molecular compound is an indication of the strength
of intermolecular forces.
14. Compare the molecules SF2 and SiF4 with respect to molecular shape and molecular polarity.
15. Predict which substance will have the higher boiling point in each of the following pairs.
Explain your predictions using intermolecular forces.
a. NH2Cl or PH2F
b. CH3F or F2
c. C4H10 or Cl2