Chapter 6
More on Chemical
Compounds
An Introduction to Chemistry
by Mark Bishop
Chapter
Map
Monatomic
Ion Names
•  Monatomic Cations
–  (name of metal)
•  Groups 1, 2, and 3 metals
•  Al3+, Zn2+, Cd2+, Ag+
–  (name of metal)(Roman numeral)
•  All metallic cations not mentioned above
•  Monatomic Anions
–  (root of nonmetal name)ide
Roots of
Nonmetals
H hydrC carbN nitrP phosphO oxS sulfSe selen-
F fluorCl chlorBr bromI iod-
Monatomic
Anions
H−
hydride
nitride N3−
phosphide P3−
oxide O2−
sulfide S2−
selenide Se2−
fluoride F−
chloride Cl−
bromide Br−
iodide I−
Polyatomic
Ions
Ion
Name
Ion
Name
NH4+
ammonium
NO3−
nitrate
OH−
hydroxide
SO42−
sulfate
CO32−
carbonate
C2H3O2−
acetate
PO43−
phosphate
Polyatomic Ions
with Hydrogen
•
•
•
•
•
HCO3−
HSO4−
HS−
HPO42−
H2PO4−
hydrogen carbonate
hydrogen sulfate
hydrogen sulfide
hydrogen phosphate
dihydrogen phosphate
Recognizing Ionic
Compounds
•  Metal-nonmetal…binary ionic compound
•  Metal-polyatomic ion
•  Ammonium-nonmetal or ammonium
polyatomic ion
Converting Ionic
Formulas to Names
•  Name
–  (name of cation) (name of anion)
Cation
Names
Metals with one possible
charge (Al, Zn, Cd, and
Groups 1, 2, 3)
name of metal
Metals with more than one
possible charge (the rest)
name(Roman numeral)
polyatomic cations (e.g.
ammonium)
name of polyatomic ion
Anion
Names
monatomic anion
(root of nonmetal name)ide
polyatomic anion
name of polyatomic ion
Converting Ionic
Names to Formulas
•  Determine the formula, including
charge, for the cation and anion.
•  Determine the ratio of the ions that
yields zero overall charge.
Monatomic
Ions
Binary
Covalent
Common
Names
– H2O, water
– NH3, ammonia
– CH4, methane
– C2H6, ethane
– C3H8, propane
Naming Binary
Covalent Compounds
•  If the subscript for the first element is
greater than one, indicate the subscript
with a prefix.
–  We do not write mono- on the first name.
–  Leave the "a" off the end of the prefixes that
end in "a" and the “o” off of mono- if they are
placed in front of an element that begins with
a vowel (oxygen or iodine).
•  Follow the prefix with the name of the first
element in the formula.
Naming Binary
Covalent Compounds
•  Write a prefix to indicate the
subscript for the second element.
•  Write the root of the name of the
second symbol in the formula.
•  Add -ide to the end of the name.
Prefixes
mon(o)
di
tri
tetr(a)
pent(a)
hex(a)
hept(a)
oct(a)
non(a)
dec(a)
Roots of
Nonmetals
H hydrC carbN nitrP phosphO oxS sulfSe selen-
F fluorCl chlorBr bromI iod-
Forms of Binary
Covalent Names
•  prefix(name of nonmetal) prefix(root of
name of nonmetal)ide
(for example, dinitrogen pentoxide)
•  or (name of nonmetal) prefix(root of
name of nonmetal)ide
(for example, carbon dioxide)
•  or (name of nonmetal) (root of
nonmetal)ide
(for example, hydrogen fluoride)
Writing Binary
Covalent 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-.
Arrhenius Acid
Definition
•  An acid is a substance that
generates hydronium ions, H3O+
(often described as H+), when
added to water.
•  An acidic solution is a solution
with a significant concentration of
H3O+ ions.
Characteristics
of Acids
•  Acids have a sour taste.
•  Acids turn litmus from blue to red.
•  Acids react with bases.
Strong Acid
and Water
When HCl dissolves in water,
hydronium ions, H3O+, and chloride
ions, Cl−, ions form.
Solution of a
Strong Acid
Types of
Acids
•  Binary acids have the general formula
of HX(aq)
–  HF(aq), HCl(aq), HBr(aq), and HI(aq)
•  Oxyacids have the general formula
HaXbOc.
–  HNO3 and H2SO4
•  Organic (carbon-based) acids
–  HC2H3O2
Acetic
Acid
Monoprotic and
Polyprotic Acids
•  If each molecule of an acid can donate
one hydrogen ion, the acid is called a
monoprotic acid.
•  If each molecule can donate two or more
hydrogen ions, the acid is a polyprotic
acid.
•  A diprotic acid, such as sulfuric acid,
H2SO4, has two acidic hydrogen atoms.
•  Some acids, such as phosphoric acid,
H3PO4, are triprotic acids.
Strong and
Weak Acids
•  Strong Acid = due to a completion
reaction with water, generates close to one
H3O+ for each acid molecule added to
water.
•  Weak Acid = due to a reversible reaction
with water, generates significantly less
than one H3O+ for each molecule of acid
added to water.
http://preparatorychemistry.com/acids_flash.htm
Weak Acid
and Water
Acetic acid reacts with water in a reversible
reaction, which forms hydronium and
acetate ions.
Solution of
Weak Acid
Strong and
Weak Acids
Sulfuric
Acid
H2SO4(aq) + H2O(l)
 H3O+(aq) + HSO4(aq)
HSO4(aq) + H2O(l)
⇌ H3O+(aq) + SO42(aq)
Acid
Summary
Binary acid
Strong
hydrochloric
acid, HCl(aq)
Weak
Hydrofluoric acid
Oxyacid
nitric acid, HNO3 other acids with
sulfuric acid,
HaXbOc
H2SO4
Organic acid
none
acetic acid,
HC2H3O2
Names and Formulas
of Binary Acids
•  Names have the general form of
hydro(root)ic acid, such as
hydrochloric acid.
•  The formulas are usually followed
by (aq), such as HCl(aq).
Names and Formulas
for Oxyacids
•  If enough H+ ions are added to a (root)ate
polyatomic ion to completely neutralize its
charge, the (root)ic acid is formed.
–  Nitrate, NO3−, goes to nitric acid, HNO3.
–  Sulfate, SO42−, goes to sulfuric acid, H2SO4.
(Note the -ur- in the name.)
–  Phosphate, PO43−, goes to phosphoric acid,
H3PO4. (Note the -or- in the name.)
Chemical
Nomenclature
•  General procedure for naming
compounds (See Table 5.5 in the
text.)
–  Step 1: Decide what type of
compound the name or formula
represents.
–  Step 2: Apply the rules for writing the
name or formula for that type of
compound.
Goal: To develop conversion factors that will
convert between a measurable property (mass)
and number of particles
Measurable Property 1

Number of Particles 1

Number of Particles 2

Measurable Property 2
Mass 1

Moles 1

Moles 2

Mass 2
Molecular
Mass
•  Whole = sum of parts
•  mass of a molecule = sum of the masses of
the atoms in the molecule
•  molecular mass = the sum of the atomic
masses of the atoms in the molecule
Molar Mass For
Molecular Compounds
•  Molecular Mass = Sum of the
atomic masses of atoms in one
molecule
⎛ (molecular mass) g molecular compound ⎞
⎜
⎟
1
mol
molecular
compound
⎝
⎠
Formula
Units
•  A formula unit of a substance is the
group represented by the substance’s
chemical formula, that is, a group
containing the kinds and numbers of
atoms or ions listed in the chemical
formula.
•  Formula unit is a general term that
can be used in reference to elements,
molecular compounds, or ionic
compounds.
Formula Unit
Examples
Formula Mass for
Ionic Compounds
•  Whole = sum of parts
•  Mass of a formula unit = sum of the masses
of the atoms in the formula unit
•  Formula mass = the sum of the atomic
masses of the atoms in the formula
Molar Mass For
Ionic Compounds
•  Formula Mass = Sum of the
atomic masses of the atoms in a
formula unit
⎛ (formula mass) g ionic compound ⎞
⎜
⎟
1mol ionic compound
⎝
⎠
Molar Mass
Development
General
Conversions
Units of One
Substance to
Units of Another
Study
Sheets
•  Write a description of the “tip-off” that
helps you to recognize the type of
problem the calculation represents.
•  Write a description of the general
procedure involved in the particular type
of problem.
•  Write an example of the type of
calculation.
Sample Study Sheet: Converting
Between Mass of Element and Mass
of Compound Containing the Element
•  Tip-off:
When you analyze the
type of unit you have and the type of
unit you want, you recognize that you
are converting between a unit
associated with an element and a unit
associated with a compound
containing that element.
Sample Study
Sheet (2)
•  General Steps
–  Convert the given unit to moles of the
first substance.
–  Convert moles of the first substance to
moles of the second substance using
the molar ratio derived from the formula
for the compound.
–  Convert moles of the second substance
to the desired units of the second
substance.
Units of Element
to Units of
Compound
Calculating
Empirical Formulas
Step 1: If you are not given mass in grams
for each element, convert the data you are
given to grams of each element.
•  This may involve simple unit conversions. For
example, you may be given pounds or
milligrams, which you convert to grams using
dimensional analysis.
•  Sometimes you are given the percentage of
each element in the compound. Assume that
you have 100 g of compound, and change the
units of the values given for the percentages
to grams.
Calculating
Empirical Formulas
Step 2: Convert grams of each element to moles by
dividing by the atomic mass of the element.
Step 3: Divide each mole value by the smallest and
round your answers to whole numbers or common
mixed fractions.
Step 4: If you have a fraction after the last step,
multiply all the mole values by the denominator of
the fraction.
Step 5: The resulting mole values correspond to the
subscripts in the empirical formula.
Calculating
Empirical Formulas
Calculating
Molecular Formulas
Step 1: If necessary, calculate the empirical
formula of the compound from the data
given.
Step 2: Divide the given molecular mass by
the empirical formula mass.
molecular mass
n=
empirical formula mass
Step 3: Multiply each of the subscripts in the
empirical formula by n to get the molecular
formula.
Calculating Molecular
Formulas Image