Transcript Chapter 9 Chemical Names and Formulas

Basic Nomenclature
Naming Monatomic Ions (Type I)
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Monatomic ions are ions consisting of
only one atom
Monatomic ions are either cations or
anions
– Cations (Charge and Naming)
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How is the ionic charge of a group 1A, 2A, or 3A
ion determined?
– The ionic charge is numerically equal to the group
number and positive (+)
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The names of group 1A, 2A, or 3A metals are
the same as the name of the metal, followed
by the word ion or cation
Naming Monatomic ions (Type I)
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Anions (Charge and Naming)
– How is the ionic charge of a group 5A, 6A,
or 7A ion determined?
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The charge of an ion in groups 5A, 6A, or 7A is
determined by subtracting 8 from the group
number
Anion names start with the stem of the
element and end in ide.
– Fluoride, chloride, bromide, iodide, oxide, sulfide
– Are the negative anions of Fluorine, Chlorine, Bromine,
Iodine, Oxygen, Sulfur
Naming Monatomic Ions (Type II)
• Mostly transition metals
– Often have more than one common
ionic charge
• Two methods are used to name ions of
the transition metals
– The stock system of naming transition metal
cations uses a Roman numeral in parentheses
to indicate the numeric value of the ionic
charge
– An older naming system uses the suffix –ous
to name the cation with the lesser charge, and
the suffix –ic to name the cation with the
greater charge
Common Type II Ion You Should Have
Memorized
Fe2+
Iron (II) Cation
Fe3+
Iron (III) Cation
Cu+
Copper (I) Cation
Cu2+
Copper (II) Cation
Co2+
Cobalt (II) Cation
Co3+
Cobalt (III) Cation
Sn2+
Tin (II) Cation
Sn4+
Tin (IV) Cation
Pb2+
Lead (II) Cation
Pb4+
Lead (IV) Cation
Hg22+
Mercury (I) Cation
Hg2+
Mercury (II) Cation
Ag+
Silver Ion
Type II cation with only one charge
Zn2+
Zinc Ion
Type II cation with only one charge
Cd2+
Cadmium Ion
Type II cation with only one charge
Examples of stock and classical naming
Symbol
Stock Name
Classical Name
Cu+
Copper(I) ion
Cuprous ion
Cu2+
Copper(II) ion
Cupric ion
Fe2+
Iron(II) ion
Ferrous ion
Fe3+
Iron(III) ion
Ferric ion
Pb2+
Lead(II) ion
Plumbous ion
Pb4+
Lead(IV) ion
Plumbic ion
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What is a major advantage of the Stock system over the old naming
system?
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The stock system gives the actual charge of the ion
Use the periodic table to write the name and formula (including charge)
for each ion formed from the element in the table below.
Element
Fluorine
Calcium
Oxygen
Sodium
Nitrogen
Name
Formula
Use the periodic table to write the name and formula (including charge)
for each ion formed from the element in the table below.
Element
Name
Formula
Fluorine
Fluoride ion
F-
Calcium
Calcium ion
Ca2+
Oxygen
Oxide ion
O2-
Sodium
Sodium Ion
Na+
Nitrogen
Nitride Ion
N3-
Polyatomic Ions
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What is a polyatomic ion?
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A polyatomic ion is tightly bound group of
atoms that behaves as a unit and carries a
charge
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Examples: NH4+, CO32-, OH-
The names of most polyatomic anions
(containing oxygen) usually end in -ite or ate
What is the difference between the anions
sulfite and sulfate?
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The sulfite ion has one less oxygen atom than the
sulfate ion
Polyatomic Ions to Memorize
Table 9.3
Polyatomic ions continued
How many atoms make up the oxalate ion
and what is its charge?
– Oxalate C2O42-
Polyatomic ions continued
How many atoms make up the oxalate ion
and what is its charge?
– Oxalate C2O42•
It is made up of 6 atoms (2 carbon atoms and 4
oxygen atoms) and has a charge of 2-.
Chemical Names and Formulas
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How can you tell that cobalt(II) chloride is a
binary ionic compound formed by a transition
metal with more than one ionic charge?
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The name includes a Roman numeral representing
the ionic charge of the transition metal cation
Write the names of these binary compounds
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PbS
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MgCl2
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Al2Se3
Chemical Names and Formulas
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How can you tell that cobalt(II) chloride is a
binary ionic compound formed by a transition
metal with more than one ionic charge?
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The name includes a Roman numeral representing
the ionic charge of the transition metal cation
Write the names of these binary compounds
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PbS
Lead(II) Sulfide
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MgCl2
Magnesium Chloride
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Al2Se3
Aluminum Selenide
Compounds with Polyatomic ions
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What is an polyatomic ion?
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How do you write the formula for a compound
containing a negative polyatomic ion
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An ion containing more than one element
Write the symbol for the cation followed by the
formula for the polyatomic ion and balance the
charges
Why are parentheses used to write the formula
Al(OH)3
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The parentheses indicate how many polyatomic
ions are needed in the formula
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Complete the table for these ionic compounds
containing polyatomic ions
Cation
Anion
NH4+
S2-
Fe3+
CO32-
Ag+
NO3-
K+
CN-
Name
Formula
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Complete the table for these ionic compounds
containing polyatomic ions
Cation
Anion
Name
Formula
NH4+
S2-
(NH4)2S
Fe3+
CO32-
Ag+
NO3-
K+
CN-
Ammonium
Sulfide
Iron III
Carbonate
Silver I
Nitrate
Potassium
Cyanide
Fe2(CO3)3
AgNO3
KCN
Naming Binary Molecular Compounds
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Two nonmetallic elements form binary
molecular compounds
Two nonmetallic elements often can bind
in more than one way
Prefixes are used to distinguish between
different molecular compounds that
contain the same element
mono-, 1; di-, 2; tri-, 3; tetra-, 4; penta-,5;
hexa-, 6; hepta-, 7; octa-, 8; nona-, 9
Naming Binary Covalent Compounds (Type III)
• Confirm the compound is a binary molecular compound
(two nonmetals)
• The name must identify the elements in the molecule
and indicate the number of each atom
• Name the element in the order listed in the formula
• Use prefixes to indicate the number of each kind of atom
• Omit the prefix mono- when the formula contains only
one atom of the first element in the name
• The suffix of the name of the second element is -ide
Naming Binary Molecular Compounds
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What are the names of the following compounds?
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BF3
N2O4
P4S7
What are the formulas for the following compounds?
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Use the prefixes in the name to tell you the subscript of each element
in the formula. Then write the correct symbols for the two elements
with the appropriate subscripts
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Carbon tetrabromide
Nitrogen triiodide
Iodine monochloride
tetraiodine nonaoxide
Notice, the less electronegative atom is always first in the
chemical formula and name
Naming and Writing Formulas for
Acids and Bases
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Acids produce hydrogen ions when
dissolved in water
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When naming acids, you can consider
them to be combinations of anions
connected to as many hydrogen ions as
are necessary to create an electrically
neutral compound
Rules for Naming Acids
• When the name of anion (X) ends in –ide, the
acid name begins with the prefix hydro-. The
stem of the anion has the suffix –ic and followed
by the word acid
– HCl = hydrochloric acid is formed from the anion
chloride
• When the anion name ends in –ite, the acid
name is the stem of the anion with the suffix –
ous, followed by the word acid.
– H2SO3 = sulfurous acid is formed from the anion
sulfite
• When the anion name ends in –ate, the acid
name is the stem of the anion with the suffix –ic
followed by the word acid
– HNO3 = nitric acid is formed from the anion nitrate
5.
Writing Formulas Acids
Acid Name
Acetic acid
Carbonic acid
Hydrochloric acid
Nitric acid
Phosphoric acid
Sulfuric acid
Formula
Anion Name
Writing Formulas Acids
Acid Name
Formula
Anion Name
Acetic acid
HC2H3O2
acetate
Carbonic acid
H2CO3
carbonate
Hydrochloric acid
HCl
Chloride
Nitric acid
HNO3
Nitrate
Phosphoric acid
H3PO4
Phosphate
Sulfuric acid
H2SO4
Sulfate
Names and formulas for Bases
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Another group of compounds is the
bases
– A base is a compound that produces
hydroxide ions when dissolved in water
– Bases are named in the same way as other
ionic compounds—the name of the cation is
followed by the name of the anion
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Example (Sodium hydroxide)