Unit 3
Compounds Review
Vocabulary
1. Octet Rule
A. neutral groups of atoms that are held together by covalent bonds
2. formula unit
B. attraction between metal atoms and the surrounding “sea of electrons”
3. valence electrons
C. shows the types and numbers of atoms combined in a single molecule of a
molecular compound
4. covalent bond
D. the simplest ratio of the crystal lattice solid
5. electronegativity
E. chemical compounds tend to form so that each atom, by gaining, losing, or
sharing electrons, has an octet of electrons (8) in its highest occupied energy
level.
6. ionic bond
F. metal atoms that gain or accept electrons; positive ion
7. cation
G. the electrons in the highest energy level (s and p block)
8. molecule
H. attraction between atoms where the electrons are transferred from one atom to
the other (a metal and non-metal element).
9. polyatomic ion
I. a negative ion
10. anion
J. a group of covalently bonded non-metal elements that as a group gain or loose
electrons
11. molecular formula
K. atoms that have gained or lost electrons to have a more stable noble gas
configuration.
12. ions
L. measure of an atom’s ability to attract electrons
13. diatomic molecule
M. a substance that conducts electricity
14. electrolyte
N. nonmetal elements that share electrons to have a more stable noble gas
configuration.
15. metallic bond
O. a molecule containing only two atoms
Compounds to Bond Types
Match the following compounds to the three bond types. Each answer may be used once, more than once, or not at all.
C) Covalent Bond
I) Ionic Bond
M) Metallic Bond
___1.
KBr
___6.
CaCl2
___11. ZnI2
___2.
Cu
___7.
Br2
___12. Ag
___3.
CO2
___8.
Na2O
___13. NaCl
___4.
Pb
___9.
SiO2
___14. C(graphite)
___5.
CH4
___10. brass (Cu + Zn)
___15. C3H8
Properties of Types of Bonds
Match the following statements to the three bond types.
Each answer may be used once, more than once, or not at all.
C) Covalent Bond
I) Ionic Bond
M) Metallic Bond
___1.
forms a crystal lattice structure, brittle
___7.
malleable and ductile
___2.
conducts electricity as a solid
___8.
conducts electricity when dissolved in water
___3.
alternating positive and negative particles
___9.
involves a transfer of electrons
___4.
sharing electrons between two atoms
___10. involved in molecules and in network solids,
___5.
positive ions in a “sea of electrons”
___11. does not usually conduct electricity
___6.
Low melting and boiling points
___ 12. Usually not soluble in water
Lewis Dots of Elements & Ions
Draw Lewis Dot Symbols of the following elements and ions:
Na
Cl
Na
K+
O
Cl
FK
I
O
S2F
Al
I
BrS
Al
Ca2+
Br
Ca
Lewis Diagrams and Polarity
1.
2.
3.
Consider the following Lewis Dot Symbols. Circle the elements (and electrons) that follow the octet rule.
State whether each molecule below is polar or non-polar. Explain to each other why you made your choice.
Which compounds have double or triple bonds?
Example: Carbon dioxide
Electronegativity difference, but
cancels out. Nonpolar
Lewis Dots of Molecules and Polarity
1.
2.
Draw the Lewis Symbols of the following molecules. Only single bonds are used.
State whether each molecule below is polar or non-polar.
O2
CH3Cl
H2O2
H2O
PH3
SiH4
CH3COOH
C2H6
CH3OH
Shape, Bond Angle, and Polarity
VSEPR Shapes: The shape and bond angle of a molecule is based on the number of bonds and pairs of lone electrons off the
central atom. Use the Lewis Structures above to determine the shape, bond angle, and polarity of each molecule.
Polarity:
Shape of Molecule (central atom)
Bond Angle
Polarity
Compounds
Bonds
Lone Pairs
Shape
O2
CH3Cl
H2O2
H2O
PH3
SiH4
CH3COOH
C2H2
CH3OH
Names and Formula - Covalent Compounds
Covalent compounds two or more _____________________ elements that __________________
1.
6.
2.
7.
3.
8.
4.
9.
5.
10.
electrons to complete an octet of valence electrons. Covalent compounds are also called
_______________________.
Rules:
1. Use _________________ to indicate the number of each kind of atom.
2. Add the ______________ ending to the second element.
3. Do not use ____________________ on the first element in the compound name.
Write the name and the formula for the following covalent compounds.
Covalent Names
Covalent Formula
1. SO2
1. disulfur hexachloride
2. P3Br4
2. dinitrogen pentoxide
3. N2O5
3. carbon tetriodide
4. CCl4
4. tetraphophorus dekoxide
5. P2I7
5. phosphorus trichloride
6. ClO2
6. trisulfur octoxide
7. SF6
7. nitrogen monoxide
Ionic Compounds
Ion Charge
The forces of attraction between oppositely charged ions in the compounds are
called ____________. Atoms that have given up electrons and are positive are
charge is called a ___________. Atoms that have gained electrons and are negative
in charge are called ______________. Ionic compounds form _______________
____________________ where oppositely charged ions line up next to one another
to minimize repulsion forces The representative particle is a
_____________________.
Ionic Compound Formula
Rules:
1.
Write the charge of each ion.
2.
Determine the correct number of each ion needed to have an overall charge of zero.
3.
Write the number of each ion by adding subscripts.
# Cations
Cation
3
NH4+
# Anions
1
Anion
3-
PO4
Ba2+
NO3-
Al3+
CO32-
Sr2+
OH-
Fe3+
C2H3O2-
Compounds
Iron (II) chloride
Sodium chloride
Copper (II) oxide
Magnesium oxide
Calcium bromide
Lead (II) sulfate
Aluminum oxide
cobalt (II) nitrate
FeF3
Na2O
K2SO4
(NH4)3N
MnO2
Cr2 (SO4)3
Formula
(NH4)3PO4
Group A Metal?
Compound name ends in -ide
Write and balance charges
More than 2 different
elements present?
Transition metal? Roman #?
Compound ends in -ide
Roman number – charge of metal atom
Polyatomic ion (-ate or –ite)
1. Identify polyatomic ion.
2. Write and balance charges
Percent Composition
Calculate the molar masses of NaOCl and Ca(NO3)2.
Calculate the percent composition of each element in the following compounds.
NaOCl
Na =  =
O =  =
Cl =  =
Ca(NO3)2
Ca =  =
N =  =
O =  =
Empirical and Molecular Formula
Empirical formula: the lowest whole number ratio of atoms in a compound.
Molecular formula: the true number of atoms of each element in the formula of a compound.
Empirical
HO
CH
NO2
Molecular
H2O2
C2H2
N2O4
Given that the empirical formula of a compound is CH and the molar mass is 104 g/mol, calculate the molecular formula.
1.
Find the mass of the empirical formula.
2.
Divide the molar mass by the mass of the empirical formula.
3.
Multiply the subscripts in the empirical formula by the difference (answer to #2).
Given that a certain compound is 69.58% Ba, 6.090% C and 24.32% O, calculate the empirical formula of this compound.
1. Assume that you have 100.00 g of the compound:
69.58% Ba = 69.58 g Ba
6.090% C = 6.090 g C
24.32% O = 24.32 g O
2.
Convert the mass of each element to moles of that element:
3.
Divide through each value by the smallest number of moles to get a ____________________:_________________ ratio,
which rounds of nicely to give the formula ___________________________.
Names and Formula for Acids
Write the formula of the acid formed from the following anions.
Anion
acid formula
anion
acid formula
ClSO42OHPO432S
C2H3O2-
anion
MnO4FNO3-
acid formula
Name the following acids:
formula
acid name
HBr
HNO3
HC2H3O2
formula
H2CO3
H2S
H3PO4
acid name
formula
HI
H2Cr2O7
HClO3
acid name
Given the anion, write the formula of the acid and then name it:
Anion
formula
acid name
S2ClNO3C2H3O2-
anion
SO42ClO3FCO32-
formula
acid name
Moles – Mass- Particles - Volume
The __________________ is the amount of substance that contains as many particles as there are in _______________________.
The amount of substance that contains the _____________________ number of particles (1 mol = 6.02 x 1023 particles). Particles
can be many units; elements are measured as ________________, covalent compounds are counted as ________________, and ionic
compounds are counted as _______________ ____________.
One mole of any gas will occupy ______________ liters at standard temperature and pressure (STP).
Moles and Mass Conversions
The molar mass is the mass of 1 mole or 6.02 x 10 23 atoms, molecules, or
formula units. The molar mass for single elements is found on the
_____________ _________________. The mass unit for a single atom is
Mole and Mass Relationships
1. Converting moles to mass
Amount of moles x Molar Mass
1 mole given
2. Converting particles to moles
Given mass x
1 mole given
Molar mass
= mass grams
(grams)
= moles given
___________ ________________ _____________ (AMU). The mass unit for
one mole of an element or compound is measured in _________________.
1.
How many grams are in 2.5 moles of sodium carbonate, Na2CO3?
2.
What is the mass of 1.25 moles of hydrogen gas, H2?
3.
How many moles are 48.5 grams of sodium chloride, NaCl?
4.
How many moles are in 96 grams of glucose, C6H12O6?
Moles and Molecule Conversions
The amount of substance that contains the _____________________ number of
particles (1 mol = 6.02 x 1023 particles). Particles can be many units; elements
are measured as ________________, covalent compounds are counted as
________________, and ionic compounds are counted as _______________
____________.
1.
Determine the number of moles in 2.4 x 10 22 molecules hydrogen gas, H2?
2.
How many moles of water are in 4.5 x 10 24 molecules water, H2O?
Mass and Molecule Conversions
1.
How many molecules of glucose are in 96 grams, C6H12O6?
2.
What is the mass of 1.25 moles of hydrogen gas, H2?
3.
How many formula units are 48.5 grams of sodium chloride, NaCl?
Mole-Particle Relationships
1. Converting moles to particles
Amount of moles x 6.02 x 1023 particles = particles given
1 mole given
2. Converting particles to moles
Given particles x
1 mole given
= moles given
6.02 x 1023 particles