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!
Ch. 7 Test Next Thursday!
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.
Ch. 7 Test Next Thursday!
Nomenclature QUIZ 1 RETAKE• Write the compound name:
1. CaBr2
2. Na2CO3
3. Ca(OH)2• Write the formula:
4. Magnesium Carbonate5. Calcium Nitrite
Write the ion name or formula that corresponds:
6. NH4 +17. SO4 -28. Sulfite9. AsO4 -310.PO4 -3
• Write the ion name or formula that corresponds:
11. Chlorate12. ClO3 -113. OH -114. Carbonate15. ClO4 -116. NO3 -117. NO2 -1 18. Sulfate19. CN -120. SO3 -2
Nomenclature QUIZ 2 RETAKE• Write the formula name:
1. NaI
2. CaO
3. NaCl
4. Ca(OH)2
5. SO3Write the formula:
6. Sodium Fluoride
7. Potassium Sulfide
8. Iron (III) Oxide
Write the nomenclature:
9. H2SO4
10.Chloric Acid11.Hydroflouric Acid12.CH3COOH13.HClO2
14.Carbonic Acid15.Sulfuric Acid16.H2SO3
17.Nitric Acid18.HCl19.H3PO4
20.H2CO3
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 amuaverage atomic mass of O: 16.00 amu
1.01 amu2 H atoms 2.02 amu
H atom
16.00 amu1 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 amu1 K atom 39.10 amu
K atom
35.45 amu1 Cl atom 35.45 amu
Cl atom
16.00 amu3 O atoms 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
A compound’s molar mass is numerically equal to its formula mass
1.01 g H2 mol H 2.02 g H
mol H
16.00 g O1 mol O 16.00 g O
mol O
molar mass of H2O molecule = 18.02 g/mol
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 H1 mol Ba 137.33 g Ba
mol Ba
16.00 g O6 mol O 96.00 g O
mol O
14.01 g2 mol N 28.02 g N
mol N
molar mass of Ba(NO3)2 = 261.35 g/mol
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem Solution
• Given: 2.50 mol O2
• Unknown: mass of O2 in grams
2
22
2
32.00 g O2.50 m 80.0ol O
mol Og O
moles O2 grams O2
amount of O2 (mol) × molar mass of O2 (g/mol) = mass of O2 (g)
16.00 g O2 mol O 32.00 g
mol O 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
13 18 2
13 18 2 13 18 213 18 2
1 mol C H Og C H O mol C H O
206.31 g C H O
moles molecules
23
13 18 2 13 18 2
6.022 10 moleculesmol C H O molecules C H O
mol
moles C13H18O2 moles C grams C
13 18 213 18 2
13 mol C 12.01 g Cmol C H O g C
mol C H O mol C
Using Chemical Formulas
Molar Mass Conversions
• Sample Problem Solution
23
2
13 18
2
2
13 18 2
6.022 10 molecules0.16mol C
9.6 10 molecules C
H Omol
H O
13 18 2
13 18 2
13 mol C 12.01 g C0.16 mol C H O
mol C H O mol C25 g C
13 18 2
13 18 213 18 2
13 18 2
1 mol C H O33 g C H O
206.31 g C H O0.16 mol C H O
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:
The mass percentage of an element in a compound is the same regardless of the sample’s size
mass of element in sample of compound100
mass of sample of compound
% element in compound
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
The percentage by mass of each element in a compound is known as the percentage composition of the compound
mass of element in 1 mol of compound100
molar mass of compound
% element in 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 Cu2Sformula molar mass mass percentage of each element