Chapter 20 Practice – Answer Key
What elements (and how many of each) make of the following compounds?
H2SO4
Hydrogen – 2, sulfur – 1, oxygen – 4
Mg(OH)2
Magnesium – 1, oxygen – 2, hydrogen - 2
SiO2
Silicon – 1, oxygen - 2
C2H5OH
Carbon – 2, hydrogen – 6, oxygen - 1
Cu(NO3)2
Copper – 1, nitrogen – 2, oxygen - 6
Draw the Lewis Dot Configuration for the following elements/ions/compounds.
H2
ClF
N2
KI
Mg2+
H:H
Ne
Describe the type of bond present in the following compounds. Be specific.
H2
Single covalent bond (nonpolar)
O2
Double covalent bond (nonpolar)
HCl
Polar covalent bond (single bond)
NaCl Ionic
How do ionic and covalent compounds compare?
Ionic bonds form between metals and nonmetals and result in neutral compounds when electrons are
given from one atom to another atom. Ionic compounds are often solid at room temperature with
crystalline structures and high melting points. Covalent compounds are when atoms share electrons
with other atoms. Covalent compounds often result in non-crystalline liquids or gases at room
temperature.
What is a molecule?
A molecule is a group of atoms that are bonded covalently.
Name the following compounds.
CuO
Copper (II) oxide
Cu(NO3)2
Copper (II) nitrate
CaSO4 ∙ 2H2O Calcium sulfate dihydrate
FePO4
Iron (III) phosphate
Fe2S3
Iron (III) sulfide
Cu(ClO3)2
Copper (II) chlorate
Ca3(PO4)2
Calcium phosphate
(NH4)2SO4
Ammonium sulfate
KBr
Potassium bromide
Identify the chemical formula for the following compounds.
Calcium fluoride
CaF2
Potassium chloride
KCl
Lithium nitride
Li3N
Dinitrogen tetroxide N2O4
Calcium carbonate
CaCO3
Sodium oxide
Na2O
Strontium nitrate pentahydrate
Lead (II) oxide
PbO
Carbon monoxide
CO
Lithium chromate
Li2CrO4
Dinitrogen pentoxide N2O5
Sr(NO3)2  5H2O