Chapters 12 Vocabulary and Reading Assignment
Please define the following terms found in chapter 12.
Bond
Ionic Bonding
Covalent Compound
Dipole moment
Single Bond
Polar Covalent Bond
Lewis structure
Double Bond
Linear Structure
Ionic Compound
Triple Bond
Covalent Bonding
Electronegativity
Octet Rule
Lone (unshared) pair
Resonance
Molecular (Geometric) Structure
Trigonal Planar Structure
Tetrahedral Structure
Valence Shell Electron Pair Repulsion (VSEPR) Model
Trigonal Pyramid
Chapter 12.1-12.3 Reading Questions:
These should be completed by November 8th.
1. Define a chemical bond.
2. What types of elements react to form ionic compounds? Give an example of the formation of
an ionic compound from its elements.
3. What type of bonding requires the complete transfer of an electron from one atom to another?
What type of bonding involves the sharing (either equally or unequally) of electrons between
atoms?
4. Describe the type of chemical bonding that exists between the atoms in the hydrogen molecule,
H2.
5. Describe the type of chemical bonding that exists between the atoms in the hydrogen fluoride
molecule, HF.
6. What do chemists mean by the term electronegativity? What does its electronegativity tell us
about the atom?
7. What does it mean to say that a bond is polar? Does the fact that a molecule possesses polar
bonds necessarily mean that the molecule itself will also be polar?
8. What is a dipole moment? Give four examples of molecules that possess dipole moments, and
draw the direction of the dipole as shown in this section.
9. Why is the presence of a dipole moment in the water molecule so important? What are some
properties of water that are determined by its polarity?
Chapter 12.6 & 12.7 Reading Questions:
These should be completed by November 12th.
1. Why are the valence electrons of an atom the only electrons likely to be involved in bonding to
other atoms?
2. Explain what the “duet” and “octet” rules are and how they are used to describe the
arrangement of electrons in a molecule.
3. How many electrons are involved when two atoms in a molecule are connected by a “double
bond”? Write the Lewis structure of a molecule containing a double bond.
4. Give the total number of valence electrons in each of the following molecules:
a. CBr4
b. NO2
c. C6H6
d. H2O2
5. Write a Lewis structure for each of the following molecules. Show all bonding valence electron
pairs as lines and all nonbonding valence electron pairs as dots.
a. NH3
b. Cl4
c. NCl3
d. SiBr4
Chapter 12.8 and 12.9 Reading Questions:
These should be completed by November 14th.
1.
2.
3.
4.
5.
6.
7.
8.
What is the geometric shape of the water molecule? How many pairs of valence electrons are
there on the oxygen atom in the water molecule? What is the approximate H—O—H bond
angle in water?
What is the geometric structure of the ammonia molecule? How many pairs of electrons
surround the nitrogen atom in NH3? What is the approximate H—N—H bond angle in
ammonia?
What is the geometric structure of the boron trifluoride molecule, BF3? How many pairs of
valence electrons are present on the boron atom in BF3? What are the approximate F—B—F
bond angles in BF3?
What is the geometric structure of the CH4 molecule? How many pairs of valence electrons are
present on the carbon atom of CH4? Refer to figure 12.11 and estimate the H—C—H bond
angles in CH4.
Why is the geometric structure of a molecule important, especially for biological molecules?
What general principles determine the molecular structure (shape) of a molecule?
Although the valence electron pairs in ammonia have a tetrahedral arrangement, the overall
geometric structure of the ammonia molecule is NOT described as being tetrahedral. Explain.
Using the VSEPR theory, predict the molecular structure of each of the following molecules:
a. CCl4
b. H2S
c. GeI4
This vocab assignment is due on November 18th.