Name_________________________________________________________Date___________Pd______
Ch 8.1-8.3 Review Study Guide
Covalent Bonding Naming and Writing Formulas for Covalent Compounds and Drawing Lewis
Structures
1 a) What is a covalent bond?
How many electrons make up a single covalent bond?
Shared electrons between nonmetal atoms. Two electrons in a single bond.
b) What is a triple covalent bond and how many electrons are involved in the triple bond?
Triple bond occurs when six electrons are shared between nonmetal atoms.
c) What kind of elements combine to form covalent compounds?
Nonmetals
d) What is a sigma bond and how is it formed? Draw a diagram using orbitals to show a sigma bond.
A sigma bond forms when orbitals from two atoms overlap end to end in order to share electrons and
form a covalent bond. The overlap occurs directly between the atoms.
e) What is a pi bond and how is it formed? ? Draw a diagram using orbitals to show a pi bond.
A pi bond forms when p-orbitals from two atoms overlap parallel (side to side) so that the
overlap occurs above and below a direct line between the atoms.
f) What is bond dissociation energy and why is it always positive in value?
Bond dissociation energy is the energy needed to break a specific covalent bond. It is always positive
because energy is needed to break the bonds.
2) a) How are bond length and bond strength related in covalent bonds?
Bond length and bond strength are related in that the shorter the bond, like a triple bond, the greater the
bond strength.
b) What is an endothermic reaction? What is an exothermic reaction? Give an example of each.
An endothermic reaction involves a net amount of energy being absorbed in order for the reaction to
occur. An exothermic reaction involves a net amount of energy being given off in order for the reaction to occur
3) Name or write the formulas for the following covalent molecules and acids:
a) SO2 ___Sulfur dioxide____________________________
b) H2SO3 ____Sulfurous acid__________________________
c) sulfur dichloride _____SCl2____________________________
d) phosphorus pentafluoride ___PF5__________
e) H2S ___hydrosulfuric acid_____________________________
f) CCl4 __carbon tetrachloride______________________________
g) HI __hydroiodic acid_______________________________
h) phosphorus acid __H3PO3___________________
i) H3AsO4 ___Arsenic acid_________________________
4) Draw Lewis structures for the following covalent compounds:
b) AsO43-
a) NH3
Looks like this except with As as central atom!
c) SiO2
d) SeCl6
Looks like this except with Se as central atom!
5) Draw the three resonance structures for AsO31- ion:
Looks like these except with As as the central atom!
6) Draw the Lewis Structure for C2H2 and mark all the sigma and pi bonds!
This structure has 4 sigma bonds to the hydrogens and one sigma and one pi bond
between the carbons.