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Types of Chemical Bonds
Academic Chemistry
Unit 7: Properties of Covalent Compounds
Textbook Readings and Homework:
6-1 Introduction to Chemical Bonding
p. 161 - 163
6-2 Covalent Bonding & Molecular Compounds
p. 164 – 175
7-1 Chemical Names and Formulas
p. 211 – 215
EOC’s p. 195 # 9, 12, 13, 39, 41, 46, 64ab and p. 235 # 9-11
P 163 #3a,b,c
p. 175 #2,3,4
p. 215 #4 f,g,h
Vocabulary:
Chemical Bond (6.1)
Ionic Bonding (6.1)
Covalent Bonding (6.1)
Non-polar Covalent Bond (6.1)
Polar Covalent Bond (6.1)
Polar (6.1)
Molecule (6.2)
Molecular Compound (6.2)
Chemical Formula (6.2)
Molecular Formula (6.2)
Diatomic Molecule (6.2)
Bond Length (6.2)
Bond Energy (6.2)
Octet Rule (6.2)
Electron-dot Notation (6.2)
Lone Pair (6.2)
Lewis Structures (6.2)
Structural Formula (6.2)
Single Bond (6.2)
Double Bond (6.2)
Triple Bond (6.2)
Resonance (6.2)
Molecular Polarity (6.5)
Objectives:
1.
2.
3.
4.
Relate the electron configuration of an atom to its chemical reactivity.
Describe the process of forming a covalent bond.
Describe the change in energy and stability that takes place as a covalent bond is formed.
Distinguish between nonpolar and polar covalent bonds based on differences in
electronegativity.
5. Draw Lewis structures to show the arrangement of valence electrons among atoms in
molecules and polyatomic ions.
6. Explain the differences between single, double, and triple covalent bonds.
7. Name simple covalent compounds using prefixes, roots, and suffixes.
Activities and Labs:
1. Lab: DHMO Research
2. Lab: Ionic vs Covalent
1
Classify the following compounds as ionic (Metal + nonmetal), covalent (nonmetal + nonmetal)
or both (compounds containing a polyatomic ion)
1. CaCl2
11.MgO
2. CO2
12.NH4Cl
3. H2O
13.HCl
4. BaSO4
14.KI
5. K2O
15.NaOH
6. NaF
16.NO2
7. Na2CO3
17.AlPO4
8. CH4
18.FeCl3
9. SO3
19.P2O5
10.LiBr
20.N2O3
2
Covalent Bonding
Covalent bonding occurs when two or more nonmetals share electrons, attempting to attain a stable
octet of electrons at least part of the time. For example:
xx
H
Cl
xx
xx
Cl
xx
+
x
.
.x
xx
H
xx
Remember that hydrogen is content with 2 electrons
Show how covalent bonding occurs in each of the following pairs of atoms. Atoms may share one, two
or three pairs of electrons.
H + H (H2)
F + F (F2)
H + S (H2S)
S + Br (SBr2)
H + O (H2O)
N + H (NH3)
3
Use the equations to correctly draw the Lewis Structure and Structural
Formula for each of the following. N = number of bonding atoms except
hydrogen.
All Single Bonds
One Double Bond
One Triple Bond
*Or Two Double Bonds
Molecule
Dot Notation
Calculation
6(N) + 2 = VE
6(N) + 2 = VE + 2
6(N) + 2 = VE + 4
Lewis Structure
IBr
CH3Br
C2HCl
SiCl4
F2O
SO3
ONCl
4
Structural Formula
CO
O2
O3
SNI
CHP
N2O2
S2Si
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Rules for Naming Binary Covalent Compounds
A binary covalent compound is composed of two different nonmetal elements. For example, a
molecule of chlorine trifluoride, ClF3 contains 1 atom of chlorine and 3 atoms of fluorine.
Rule 1. The element with the lower group number is written first in the name; the element with
the higher group number is written second in the name.
Rule 2. If both elements are in the same group, the element with the higher period number is
written first in the name.
Rule 3. The second element in the name is named as if it were an anion, i.e., by adding the
suffix -ide to the name of the element.
Rule 4. Greek prefixes (see the table given to you in class) are used to indicate the number of
atoms of each nonmetal element in the chemical formula for the compound.
Exception: if the compound contains one atom of the element that is written first
in the name, the prefix "mono-" is not used.
Name the following covalent compounds.
Formula
Name
Formula
1
NO3
9
NF3
2
N2O5
10
CO2
3
S2Cl2
11
SO3
4
XeO3
12
CCl4
5
Cl2O7
13
NH3
6
HBr
14
PO2
7
P4O10
15
SO2
8
P4O6
16
CO
6
Name
Writing Formulas for Covalent Compounds
Follow these steps for writing formulas for binary covalent compounds when you are given a
systematic name. Notice that they are the reverse of the steps for writing names from
chemical formulas.
Write the symbols for the elements in the order mentioned in the name.
Write subscripts indicated by the prefixes. If the first part of the name has no prefix,
assume it is mono-.
Write the formulas for these covalent compounds.
Name
Formula
Name
1 Dinitrogen pentoxide
10 Tribromine octoxide
2 Carbon monoxide
11 Dichlorine pentoxide
3 Hydrogen iodide
12 Carbon tetrafluoride
4 Iodine bromide
13 Sulfur hexafluoride
5 Diphosphorus
pentoxide
14 Carbon dioxide
6 Phosphorous
tribromide
15 Carbon tetrahydride
7 Diboron silicide
16 Dinitrogen trioxide
8 Chlorine dioxide
17 Nitrogen trifluoride
9 Xenon tetrafluoride
18 Disilicon hexabromide
Formula
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Covalent Compound Scavenger Hunt
1) List three covalent objects that can be found in the sinks in this classroom:
a) ________________________________________________
b) ________________________________________________
c) ________________________________________________
2) Haikus are three line Japanese poems where the first line has five syllables, the second has seven
syllables, and the third has five syllables. Write a haiku about how the electrons behave when a
covalent compound is formed.
3) Find one example of an edible covalent compound somewhere in the book and give its name,
molecular formula, and empirical formula.
Name: ________________________________________________
Molecular formula: ____________________________________________
Empirical formula: ____________________________________________
4) Give the names and molecular formulas of five covalent compounds that has “oxide” somewhere in
the name. These compounds must actually exist, so don’t just make them up!
a) ________________________________________________
b) ________________________________________________
c) ________________________________________________
d) ________________________________________________
e) ________________________________________________
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5) Describe how a blind person might determine if a compound is ionic or covalent if they were
working alone in a laboratory.
6) Ask somebody who is not in your group the following question: “If you were a chemical, would
you want to be ionic or covalent, and why?” Write their answer below:
7) Draw the Lewis structures of any three covalent molecules whose formulas can be found in the
Appendix of your book:
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