GENERAL CHEMISTY CHAPTER 9 Practice Assessment
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Calculate the Δ EN for the following bonds and classify the bonds as ionic, non-polar
covalent, or polar covalent: C–P, Ba–N, Pd–Cl, Ge–Se.
Describe AND explain the trends in electronegativity within a group and a period on the
periodic table.
Do you expect CaO or CaN to have a higher melting point? Why?
Ammonia, NH3, has 4 pairs of electrons around the central nitrogen atom, but it is not
classified as a tetrahedral geometry. State the molecular shape/geometry of ammonia, and
explain why the tetrahedral geometry has become distorted.
Draw the Lewis Dot Diagram for water. Include the correct location of the partial charges on
the molecule. State the molecular shape/geometry of water. Why does water exhibit strong
surface tension, and an ability to dissolve many other compounds?
When we compare the geometry of methane, CH4, to methyl chloride, CH3Cl, we see that
they are both tetrahedral. Which molecule would you expect to have the higher boiling point,
and why?
Draw the Lewis Dot Diagram for the molecule CH2O. State the molecular shape(s)/geometry
of this molecule. Is the molecule polar or non-polar? How do you know?
Draw Lewis Dot Diagrams for the following molecules/ions and state the molecular
shape/geometry of each: N31- , Cl2S, SeO2
Compare and contrast the physical properties of non-polar covalent, polar covalent
and ionic compounds. Use examples to supplement your answer.