Chapter 7- Chemical
Formulas and Chemical
Compounds
Ban Dihydrogen Monoxide!
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Colorless, odorless, tasteless
Kills uncounted thousands of people every year.
Most deaths caused by accidental inhalation
Prolonged exposure to its solid form causes severe
tissue damage.
Symptoms of ingestion can include
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excessive sweating and urination,
a bloated feeling,
nausea,
vomiting
body electrolyte imbalance.
For those who have become dependent, withdrawal
means certain death.
Ban Dihydrogen Monoxide!
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Also known as hydroxl acid
Major component of acid rain
Contributes to the "greenhouse effect."
May cause severe burns.
Contributes to the erosion of our natural landscape.
Accelerates corrosion and rusting of many metals.
May cause electrical failures and decreased
effectiveness of automobile brakes.
Been found in excised tumors of terminal cancer
patients.
Is now an ingredient in most foods and beverages
Ban Dihydrogen Monoxide!
Based on the evidence presented in the
previous two slides, do you support the
banning of dihydrogen monoxide?
 Write at least two sentences stating your
reasoning.
 Please sign the petition!
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What is Dihydrogen Monoxide?
Chemical Formulas
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Indicate the relative number of atoms or
ions of each kind in a chemical compound
8 C atoms
C8H18
1 Mg2+ ion
MgCl2
1 Ca2+ ion
Ca(OH)2
18 H atoms
2 Cl- ions
2 OH- ions
Monatomic Ions
Ions formed from a single atom
 Usually have noble gas configurations
 That’s how we determine its charge
 Example:
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Li: 1s22s1
 Li+: 1s2 or [He]
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Table on p.221 on monatomic ions
Naming Monatomic Cations
Use the element’s name!
 Yes, it’s that simple!
 Example:
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Cs+ = cesium
 Al3+ = aluminum
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Naming Monatomic Anions
Drop the ending of the element’s name
 Add the ending –ide
 Examples:
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Cl- = chloride
 N3- = nitride
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Naming Monatomic Ions
K+
 S2 Rb+
 O2 I Ba2+
 Cu+
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potassium
 sulfide
 rubidium
 oxide
 iodide
 barium
 copper
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Binary Ionic Compounds
Compounds composed of two ions
 Total numbers of positive charges and
negative charges must be equal
 Examples:
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NaCl
 KBr
 CaF2
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Writing Binary Ionic Compounds
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Write the symbols for the ions side by
side. Write the cation first.
Al3+ O2
Cross over the charges to use as the
subscript for the other ion.
Al3+ O2Al2 O3
Writing Binary Ionic Compounds
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Check the subscripts and divide them to
give the smallest whole number ratio of
ions.
Al2O3
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Write the formula!
Al2O3
Writing Binary Ionic Compounds
Zinc iodide
 Barium fluoride
 Lithium oxide
 Calcium oxide
 Magnesium bromide
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ZnI2
 BaF2
 Li2O
 CaO
 MgBr2
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Naming Binary Ionic Compounds
Give name of cation first
 Then name the anion
 Al2O3
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Name of cation: aluminum
 Name of anion: oxide
 Name of compound: aluminum oxide
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Naming Binary Ionic Compounds
BaI2
 ZnF2
 K2O
 MgO
 CaBr2
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Barium iodide
 Zinc fluoride
 Potassium oxide
 Magnesium oxide
 Calcium bromide
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Cations With Different Charges
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Some elements form two or more cations
with different charges
Fe2+ and Fe3+
 Iron (II) and Iron (III)
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Naming compounds
FeO and Fe2O3
 Iron (II) oxide and Iron (III) oxide
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Name the Following Compounds
CuO
 CoF3
 SnI4
 FeS
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Copper (II) oxide
 Cobalt (III) fluoride
 Tin (IV) iodide
 Iron (II) sulfide
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Quiz- Name the Following
Compounds
1.
2.
3.
4.
5.
K2S
AgBr
Na2O
FeCl2
BaS
6.
7.
8.
9.
10.
Lithium fluoride
Silver iodide
Iron (III) oxide
Magnesium iodide
Gold chloride
Polyatomic Ions
Ions that contain two or more atoms
 Most are negatively charged
 List of polyatomic ions is on handout
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**MEMORIZE THEM!!!**
Examples:
CN- cyanide
 HCO3- hydrogen carbonate (bicarbonate)
 NH4+ ammonium
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Polyatomic Ions
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You will need to memorize the following:
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Ammonium
Acetate
Hydroxide
Nitrite
Nitrate
Bicarbonate
Carbonate
Chromate
Sulfate
Phosphate
NH4+1
C2H3O2-1
OH-1
NO2-1
NO3-1
HCO3-1
CO3-2
CrO4-2
SO4-2
PO4-3
Oxyanions
Polyatomic ions that contain oxygen
 Name depends on number of oxygen
atoms
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Oxyanions (cont.)
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If two oxyanionsMost oxygens: -ate
 Least oxygens: -ite
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Example
NO3- : nitrate
 NO2- : nitrite
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Oxyanions (cont.)
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If more than two oxyanions
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Most oxygens: “Per- …. –ate”
“-ate”
“-ite”
Least oxygens: “Hypo- …. –ite”
Example
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ClO4- : perchlorate
ClO3- : chlorate
ClO2- : chlorite
ClO- : hypochlorite
Polyatomic Ion Quiz
Sodium hypochlorite
 Potassium sulfate
 Magnesium peroxide
 Ammonium chloride
 Lithium nitrate
 Potassium phosphate
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NaClO
 K2SO4
 MgO2
 NH4Cl
 LiNO3
 K3PO4
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Polyatomic Ion Quiz
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Bicarbonate
Acetate
Bisulfite
Permanganate
Nitrite
Cyanide
Hydroxide
Bisulfate
Nitrate
What’s your favorite polyatomic ion?
Binary Molecular Compounds
Composed of molecules (covalently
bonded!)
 A nonmetal bonded to another nonmetal
 Examples:
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SO3
 ICl3
 CH4
 H2O
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Prefixes for Naming Binary
Molecular Compounds
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1
2
3
4
5
6
7
8
9
10
monoditritetrapentahexaheptaoctanonadeca
Naming Binary Molecular
Compounds
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Which element goes first?
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Second element
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Smaller group number
If same group- greater period number
Use prefix only if there is more than one atom
Prefix indicating number of atoms + root of the name
of the element + -ide
General order of elements in binary compounds:
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C, P, N, H, S, I, Br, Cl, O, F
Naming Binary Molecular
Compounds
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Examples:
SO3 – sulfur trioxide
 BrCl3 – bromine trichloride
 PBr5 – phosphorus pentabromide
 N2O5 – dinitrogen pentoxide
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Naming Binary Molecular
Compounds
N2O
 CCl4
 NO
 CO2
 N2O3
 P4O10
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Dinitrogen monoxide
 Carbon tetrachloride
 Nitrogen monoxide
 Carbon dioxide
 Dinitrogen trioxide
 Tetraphosphorus decoxide
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Naming Binary Molecular
Compounds- More Practice!
Disulfur dioxide
 Silicon tetrafluoride
 Sulfur monoxide
 Phosphorus trioxide
 Boron trifluoride
 Diphosphorus pentoxide
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S2O2
 SiF4
 SO
 PO3
 BF3
 P2O5
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Acids
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Acid- a type of molecular compound
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Two types
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Binary acids- made up of two elements- hydrogen, and one
of the halogens (F, Cl, Br, I)
Oxyacids- contain hydrogen, oxygen, and a third element
Examples
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Binary acids:
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HCl- hydrochloric acid; HF- hydrofluoric acid
Oxyacids:
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H2SO4: sulfuric acid
HNO3: nitric acid
Formula Mass
The sum of the atomic masses of all
atoms represented in its formula
 Units = amu (atomic mass units)
 Example: What is the formula mass of
water?
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2 H atoms @ 1.01 amu each = 2.02 amu
 1 O atom @ 16.00 amu each = 16.00 amu
 Total mass of water = 16.00 + 2.02 = 18.02
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Formula Mass
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Find the formula mass of the following:
KClO3
 H2SO4
 Mg(NO3)2
 C12H22O11
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Molar Mass
The mass in grams of one mole of a
substance
 If we have 1 mole of H2O, we have
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2 moles of H atoms
 1 mole of O atoms
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Molar Mass (cont.)
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How many moles of each atom are in the
following?
CaCl2
 NaOH
 KMnO4
 NH4OH
 Mg(NO3)2
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Molar Mass (cont.)
Once we know the number of moles of
each atom, we can calculate the molar
mass.
 In H2O:
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2 moles H
x 1.01 g H = 2.02 g H
1 mole H
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1 mole O
x 16.00 g O = 16.00 g O
1 mole O
Molar Mass (cont.)
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Total mass of 1 mole H2O
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2.02 g + 16.00 g = 18.02 g/mol
Molar Mass (cont.)
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Determine the molar mass of the following:
CaCl2
 NaOH
 KMnO4
 NH4OH
 Mg(NO3)2
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Molar Mass as a Conversion Factor
Can use molar mass as a conversion
factor to determine number of moles
 How many moles of H2O are in 34.32 g?
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Molar Mass as a Conversion Factor
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How many molecules of NaCl can be
found in a sample containing 45.43 g?
Molar Mass as a Conversion Factor
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How many carbon atoms are in a 23.43 g
sample of CO2?
Fun With Conversions!
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Ibuprofen, C13H18O2, is the active
ingredient in Advil.
Find its molar mass
 If the tablets in the bottle contain a total of 33
g of ibuprofen, how many moles of ibuprofen
are in the bottle?
 How many molecules of ibuprofen are in the
bottle?
 What is the total mass in grams of carbon in
33 g of ibuprofen?
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