Mrs. Evans Chemistry Final Exam Review
Chapter 7
7.1 Ions
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To find the number of valence electrons in an atom of a representative element, simply look
at its group number..
 Atoms of the metallic elements tend to lose their valence electrons, leaving a complete octet
in the next-lowest energy level. Atoms of some nonmetallic elements tend to gain electrons
to achieve a complete octet..
 An atom’s loss of valence electrons produces a positively charged cation..
 The gain of electrons by a neutral atom produces negatively charged anion..
7.2 Ionic Bonds and Ionic Compounds
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Although they are composed of ions, ionic compounds are electrically neutral..
 Most ionic compounds are crystalline solids at room temperature, and they generally have
high melting points. Ionic compounds can conduct an electric current when melted or
dissolved in water..
7.3 Bonding in Metals
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The valence electrons of metal atoms can be modeled as a sea of electrons.
 Metal atoms are arranged in very compact and orderly patterns..
 Alloys are important because their properties are often superior to those of their component
elements..
Vocabulary Review
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alloys
chemical formula
electron dot structure
formula unit
halide ion
ionic bonds
ionic compounds
metallic bonds
octet rule
valence electron
Chapter 8
Key Concepts
8.1 Molecular Compounds
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Molecular compounds tend to have relatively low melting and boiling points..
 A molecular formula shows how many atoms of each element a molecule contains..
8.2 The Nature of Covalent Bonding
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Electron sharing occurs so that atoms attain the configurations of noble gases..
An electron dot structure shows the shared electrons of a covalent bond by a pair of dots..
Atoms form double or triple bonds by sharing two or three pairs of electrons..
In a coordinate covalent bond, the shared electron pair comes from a single atom..
A large bond dissociation energy corresponds to a strong covalent bond..
In ozone, the bonding of oxygen atoms is a hybrid of the extremes represented by the
resonance forms..
The octet rule is not satisfied in molecules with an odd number of electrons, and in
molecules where an atom has less, or more, than a complete octet of valence electrons..
solid requires breaking covalent bonds throughout the solid..
Vocabulary
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bond dissociation energy
covalent bond
coordinate covalent bond
diatomic molecule
double covalent bond
molecular compound
molecular formula
molecule
polyatomic ion
single covalent bond
structural formula
triple covalent bond
Chapter 9
Key Concepts
9.1 Naming Ions
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When the metals in Groups 1A, 2A, and 3A lose electrons, they form cations with positive
charges equal to their group number..
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The charge of any ion of a Group A nonmetal is determined by subtracting 8 from the group
number..
 The charges of cations of many transition metal ions must be determined from the number
of electrons lost. When a cation can have more than one ionic charge, a Roman numeral is
used in the name to indicate the charge..
 The names of most polyatomic anions end in -ite or -ate..
9.2 Naming and Writing Formulas for Ionic Compounds
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The name of a binary ionic compound is the cation name followed by the anion name..
 To write the formula for a binary ionic compound, write the symbol for the cation and then
the anion. Then balance the charges..
 To write formulas for compounds containing polyatomic ions, write the symbol for the metal
ion followed by the formula for the polyatomic ion and balance the charges..
 To name a compound containing a polyatomic ion, state the cation first and then the anion..
9.3 Naming and Writing Formulas for Molecular Compounds
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Prefixes show how many atoms of each element are present in a molecule of a binary
compound..
 To write the formula for a binary molecular compound, write the symbols for the elements
and use the prefixes to determine the subscripts. Omit mono- for a single atom..
9.4 Naming and Writing Formulas for Acids and Bases
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An acid is a combination of a monatomic or polyatomic anion with sufficient hydrogen atoms
to make the compound electrically neutral. Acids are named as shown in Table 9.5..
 A base is a combination of a cation with as many hydroxide ions as are needed to make the
compound electrically neutral. Bases are named in the same way as other ionic
compounds..
9.5 The Laws Governing Formulas and Names
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The ways that compounds form are summed up in two laws: the law of definite proportions
and the law of multiple proportions..
 To name a compound or write its formula, follow the flowcharts in Figures 9.20 and 9.22 to
the correct name or formula..
Vocabulary
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binary compound
law of definite proportions
law of multiple proportions
monatomic ion
polyatomic ion
Chapter 10
Key Concepts
10.1 The Mole: A Measurement of Matter
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Three methods for measuring the amount of a substance are by count, by mass, and by
volume..
 A mole of any substance always contains Avogadro’s number of representative particles, or
6.02 × 1023 representative particles..
 The atomic mass of an element expressed in grams is the mass of a mole of the element..
 To calculate the molar mass of a compound, find the number of grams of each element
contained in one mole of the compound. Then add the masses of the elements in the
compound..
10.2 Mole–Mass and Mole–Volume Relationships
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The molar mass of an element or compound is the conversion factor for converting between
the mass and the number of moles of a substance..
 One mole of any gas occupies a volume of 22.4 L at standard temperature and pressure.
One mole of any substance contains Avogadro’s number of particles, so 22.4 L of any gas
at STP contains 6.02 × 1023 representative particles of that gas..
10.3 Percent Composition and Chemical Formulas
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To determine the percent by mass of any element in a given compound, divide the
element’s mass by the mass of the compound and multiply by 100%..
 An empirical formula of a compound is the simplest whole-number ratio of atoms of the
elements in the compound..
 The molecular formula of a compound is either the same as its experimentally determined
empirical formula, or it is a simple whole-number multiple of it..
Vocabulary
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Avogadro’s hypothesis
Avogadro’s number
empirical formula
molar mass
molar volume
mole (mol)
percent composition
representative particle
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standard temperature and pressure (STP)
Key Equations
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Chapter 11
Key Concepts
11.1 Describing Chemical Reactions
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To write a word equation, write the names of the reactants to the left of the arrow separated
by plus signs; write the names of the products to the right of the arrow, also separated by
plus signs..
 To write a skeleton equation, write the formulas for the reactants to the left of the yields sign
and the formulas for the products to the right..
 After writing the skeleton equation, use coefficients to balance the equation so that it obeys
the law of conservation of mass..
11.2 Types of Chemical Reactions
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The five general types of reactions are combination, decomposition, single-replacement,
double-replacement, and combustion..
The number of elements and/or compounds reacting is a good indicator of possible reaction
type and thus possible products..
In a combination reaction, there is always a single product..
A decomposition reaction involves the breakdown of a single compound into two or more
simpler substances..
In a single-replacement reaction, both the reactants and the products are an element and a
compound..
A double-replacement reaction generally takes place between two ionic compounds in
aqueous solution..
A combustion reaction always involves oxygen as a reactant..
11.3 Reactions in Aqueous Solution
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A net ionic equation shows only those particles involved in the reaction and is balanced with
respect to mass and charge..
 You can predict the formation of a precipitate by using the general rules for solubility of ionic
compounds..
Vocabulary Review
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balanced equation
chemical equation
coefficients
combination reaction
combustion reaction
complete ionic equation
decomposition reaction
double-replacement reaction
net ionic equation
single-replacement reaction
skeleton equation
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spectator ion
Chapter 12
Key Concepts
12.1 The Arithmetic of Equations
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A balanced chemical equation provides the same kind of quantitative information that a
recipe does..
 Chemists use balanced chemical equations as a basis to calculate how much reactant is
needed or product is formed in a reaction..
 A balanced chemical equation can be interpreted in terms of different quantities, including
numbers of atoms, molecules, or moles; mass; and volume..
 Mass and atoms are conserved in every chemical reaction..
12.2 Chemical Calculations
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In chemical calculations, mole ratios are used to convert between moles of reactant and
moles of product, between moles of reactants, or between moles of products..
 In a typical stoichiometric problem, the given quantity is first converted to moles. Then the
mole ratio from the balanced equation is used to calculate the moles of the wanted
substance. Finally, the moles are converted to any other unit of measurement related to the
unit mole..
12.3 Limiting Reagent and Percent Yield
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In a chemical reaction, an insufficient quantity of any of the reactants will limit the amount of
product that forms..
 The percent yield is a measure of the efficiency of a reaction performed in the laboratory..
Vocabulary Review
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actual yield
excess reagent
limiting reagent
mole ratio
percent yield
stoichiometry
theoretical yield
Key Equations
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mole-mole relationship for aG → bW:
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