Webquest Review
Part Two: View “How can I tell the difference between ionic and covalent
compounds?”
3. Summarize the difference between ionic and covalent compound
composition.
Ionic compounds always contain a metal cation, and covalent compounds do
not contain metals. Covalent compounds contain only nonmetal elements.
Part Three: Ionic Compounds
A: View “Formation of Ions and Ionic Bonds.”
4. Explain how Mg3(PO4)2 is a neutral compound.
Three magnesium ions with +2 charges combine with two phosphate ions
with -3 charge to produce a neutral compound. The overall +6 cancels out
the overall -6 charge.
5. How and why does aluminum form a cation?
Aluminum has a relatively low ionization energy due to its small nucleus. It
loses three electrons easily to become stable having a full outer energy level.
It’s valence energy level becomes the 2nd , and aluminum’s electron cloud will
look like neon.
B: View “Writing and Naming Ionic Compounds.”
6. Write formulas for the following:
a. magnesium nitride Mg3N2
b. iron (II) hydroxide Fe(OH)2
c. ammonium sulfide (NH4)2S
d. calcium chlorate Ca(ClO3)2
7. Name the following:
a. KNO3 potassium nitrate
b. CuSO4 copper (II) sulfate
c. AgBr silver bromide
d. CoPO4 cobalt (III) phosphate
C: View “Analyzing Ionic Compounds: Higher-level Thinking.”
8. How many carbonate ions are in CaCO3? 1
9. If GdO exists and Dy(NO3)4 exists, what is the formula for gadolinium
nitrate? Gd(NO3)2
Part Four: Covalent Compounds
A: View “Writing and Naming Covalent Compounds.”
10. Name the following:
a. NF3
nitrogen trifluoride
b. SiO2
silicon dioxide
c. N2O5
dinitrogen pentaoxide
d. C3H8
tricarbon octahydride
11. Write formulas for the following:
a. dichlorine heptasulfide
Cl2S7
b. carbon monoselenide
CSe
c. silicon tetrabromide
SiBr4
d. phosphorus trichloride
PCl3
B: View “Drawing Lewis dot structures.”
12. Draw all of the resonance structures for the nitrate ion.
13. How many lone pairs of electrons exist in sulfur dioxide? 6
C: View “VSEPR – Valence Shell Electron Pair Repulsion.”
14. How many areas of high electron density surround the central atom in
NH3? 4
15. What is the molecular shape of SO3 molecule? Trigonal planar
16. Why is water a bent molecule? It has four regions of electron density.
Two of the regions are bonds, and two of the regions are lone electron
pairs.
D: View “Electronegativity Difference and Polarity.”
17. Is silicon tetrafluoride a polar molecule? no
18. Is ammonia (NH3) a polar molecule? Draw the structure.
Yes, the molecule is polar.
The lone pair of electrons on the
nitrogen atom is different from the
other sides. The nitrogen is the
negative pole, and the hydrogens
are positive.
19. Is carbon dioxide a polar molecule? Draw the structure.
No, the molecule is not polar.
E: View “Intermolecular Forces.”
20. Explain why magnesium chloride should dissolve in water.
Magnesium chloride is an ionic compound, therefore it falls into the polar
category. Water is a polar covalent compound. Due to the attractions
between the charged particles of magnesium chloride and the partially
charged portions of water, the two will mix easily.
21. Which of the following would be the most difficult to boil: H2O, CH3Cl, CO2
Why? Water will be the most difficult to boil because it has the strongest
intermolecular forces. Water will experience hydrogen bonding, which is
stronger than polar CH3Cl’s dipole-dipole force and nonpolar CO2’s
dispersion forces.
22. Carbon tetrachloride experiences dispersion forces. Why?
Carbon tetrachloride is a nonpolar molecule due to the four chlorine atoms
pulling the electron density evenly in all directions. Nonpolar molecules
experience dispersion forces.
F: View “Naming and Writing Formulas for Acids.”
23. Name the following acids:
a. H2CO3
carbonic acid
b. H2S
hydrosulfuric acid
c. H3PO3
phosphorous acid
d. H3P
hydrophosphoric acid
24. Write the formula for the following acids.
a. Acetic acid
HC2H3O2
b. Hydrochloric acid HCl
c. Nitrous acid
HNO2
d. Nitric acid
HNO3
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