Wednesday, November 28
16-30 Compound Naming Problems:
Questions?
31-40 = Homework Tonight
Must complete sheet to retake Quiz 1 & 2
Thursday= Polyatomic Ions (Quiz #1 Retake)
Friday= Acids (Quiz #2 Retake)
Take out Ch.7 ½ Packet from yesterday
Thursday, November 29
Turn in Compound Naming Race sheet
at Front if you intend to retake quiz
Friday= Acids (Quiz #2 Retake)
Take out sheet of paper, title “Polyatomic Ions
(Quiz #1 Retake)”
YOU WILL NEED CALCULATOR TODAY!
Friday, November 30
Take out sheet of paper, title
“Acids (Quiz #2 Retake)” if you are retaking quiz 2
You will need Formula Mass notes and calculator
today.
•
Nomenclature QUIZ 1 RETAKE
Write the compound name:
1. CaBr2
2. Na2CO3
3. Ca(OH)2
•
Write the formula:
4. Magnesium Carbonate
5. Calcium Nitrite

Write the ion name or formula that corresponds:
6.
7.
8.
9.
10.
NH4 +1
SO4 -2
Sulfite
AsO4 -3
PO4 -3
•
Write the ion name or formula that corresponds:
11. Chlorate
12. ClO3 -1
13. OH -1
14. Carbonate
15. ClO4 -1
16. NO3 -1
17. NO2 -1
18. Sulfate
19. CN -1
20. SO3 -2
Nomenclature QUIZ 2 RETAKE
•
Write the formula name:
1.
2.
3.
4.
5.
NaI
CaO
NaCl
Ca(OH)2
SO3
Write the formula:
6.
7.
8.
Sodium Fluoride
Potassium Sulfide
Iron (III) Oxide

Write the nomenclature:
9. H2SO4
10.Chloric Acid
11.Hydroflouric Acid
12.CH3COOH
13.HClO2
14.Carbonic Acid
15.Sulfuric Acid
16.H2SO3
17.Nitric Acid
18.HCl
19.H3PO4
20.H2CO3
Using
Chemicaland
Formulas
Chemical
Formulas
Compounds
Using Chemical Formulas
 Chemical Formulas
 A chemical formula indicates
 the elements present in a compound
 the relative number of atoms or ions of each element present in a
compound
 Chemical formulas also allow chemists to calculate a
number of other characteristic values for a compound:
 formula mass
 molar mass
 percentage composition
Using Chemical Formulas
Formula Masses
 The formula mass of any molecule, formula unit, or ion is
the sum of the average atomic masses of all atoms
represented in its formula
formula mass of water, H2O
average atomic mass of H: 1.01 amu
average atomic mass of O: 16.00 amu
1.01 amu
2 H atoms 
 2.02 amu
H atom
16.00 amu
1 O atom 
 16.00 amu
O atom
average mass of H2O molecule = 18.02 amu
Using Chemical Formulas
• Formula Masses
• The mass of any unit represented by a chemical
formula (H2O, NaCl) can be referred to as the formula
mass
Using Chemical Formulas
Formula Masses
• Sample Problem
• Find the formula mass of potassium chlorate, KClO3
Using Chemical Formulas
Formula Masses
• Sample Problem Solution
• The mass of a formula unit of KClO3 is found by adding the
masses of one K atom, one Cl atom, and three O atoms
39.10 amu
 39.10 amu
K atom
35.45 amu
1 Cl atom 
 35.45 amu
Cl atom
1 K atom 
3 O atoms 
16.00 amu
 48.00 amu
O atom
formula mass of KClO3 = 122.55 amu
The MOLE
• What is a mole?
• What is a mole of apples?
• What is a mole of carbon?
• What is a mole of H2O?
Using Chemical Formulas
• Molar Masses
• The molar mass of a substance is equal to the mass in
grams of one mole, or approximately 6.022 × 1023
particles, of the substance
• The molar mass of a compound is calculated by adding
the masses of the elements present in a mole of the
molecules or formula units that make up the compound
Molar Masses
 One mole of water molecules contains exactly two moles
of H atoms and one mole of O atoms. The molar mass of
water is calculated as follows
2 mol H 
1 mol O 
1.01 g H
 2.02 g H
mol H
16.00 g O
 16.00 g O
mol O
molar mass of H2O molecule = 18.02 g/mol
 A compound’s molar mass is numerically equal to its
formula mass
Using Chemical Formulas
Formula Masses
• Sample Problem
• What is the molar mass of barium nitrate, Ba(NO3)2
Using Chemical Formulas
Formula Masses
• Sample Problem Solution
• One mole of barium nitrate, contains one mole of Ba, two moles
of N (1 × 2), and six moles of O (3 × 2)
137.33 g H
 137.33 g Ba
mol Ba
14.01 g
2 mol N 
 28.02 g N
mol N
1 mol Ba 
16.00 g O
6 mol O 
 96.00 g O
mol O
molar mass of Ba(NO3)2 = 261.35 g/mol
Using Chemical Formulas
• Molar Mass Conversions
Molar Mass Conversions
• Sample Problem
• What is the mass in grams of 2.50 mol of oxygen gas (O2)
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem Solution
• Given: 2.50 mol O2
• Unknown: mass of O2 in grams
moles O2
grams O2
amount of O2 (mol) × molar mass of O2 (g/mol) = mass of O2 (g)
2 mol O 
16.00 g O
 32.00 g O2
mol O
32.00 g O2
2.50 mol O2 
 80.0 g O2
mol O2
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem
• Ibuprofen, C13H18O2, is the active ingredient in many
nonprescription pain relievers. Its molar mass is 206.31 g/mol
• If the tablets in a bottle contain a total of 33g 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 33g of ibuprofen?
Molar Mass Conversions
• Sample Problem Solution
• Given: 33g of C13H18O2, molar mass 206.31 g/mol
• Unknown: moles C13H18O2
molecules C13H18O2
total mass of C
Molar Mass Conversions
• Sample Problem Solution
grams
moles
1 mol C13H18O2
g C13H18O2 
 mol C13H18O2
206.31 g C13H18O2
moles
molecules
6.022  1023 molecules
mol C13H18O2 
 molecules C13H18O2
mol
moles C13H18O2
moles C
grams C
13 mol C
12.01 g C
mol C13H18O2 

 gC
mol C13H18O2
mol C
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem Solution
33 g C13H18O2 
1 mol C13H18O2
 0.16 mol C13H18O2
206.31 g C13H18O2
6.022  10 23 molecules
0.16mol C13H18O2 

mol
9.6  10 22 molecules C13H18O2
0.16 mol C13H18O2 
13 mol C
12.01 g C

 25 g C
mol C13H18O2
mol C
Percentage Composition
 It is often useful to know the percentage by mass of a
particular element in a chemical compound
 To find the mass percentage of an element in a
compound, the following equation can be used:
mass of element in sample of compound
 100 
mass of sample of compound
% element in compound
 The mass percentage of an element in a compound is the
same regardless of the sample’s size
Percentage Composition
 The percentage of an element in a compound can be
calculated by determining how many grams of the element
are present in one mole of the compound
mass of element in 1 mol of compound
 100 
molar mass of compound
% element in compound
 The percentage by mass of each element in a compound is
known as the percentage composition of the compound
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem
• Find the percentage composition of copper(I) sulfide, Cu2S
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem Solution
• Given: formula, Cu2S
• Unknown: percentage composition of Cu2S
formula
molar mass
mass percentage of each element
Molar Mass Conversions
copper(I) sulfide, Cu2S
• Sample Problem Solution
2 mol Cu 
1 mol S 
63.55 g Cu
 127.1 g Cu
mol Cu
32.07 g S
 32.07 g S
mol S
Molar mass of Cu2S = 159.2 g
127.1 g Cu
 100  79.85% Cu
159.2 g Cu2S
32.07 g S
 100  20.15% S
159.2 g Cu2S