Song

If I had a million dollars…
You are an incredibly valuable student and I want to reward you. You have 2 options for receiving your reward:
Option 1: You can either come to school for 10 days straight and receive one million dollars (regular 7 hour school day) or
Option 2: You can earn a dollar per second up to one million dollars.
You would like to buy an elite condo in the Bahamas that costs exactly one million dollars. Which deal will allow you to purchase the condo first?

How many Apple Jacks are in the container? (NO counting!)
 On your white boards, you and your partner will develop a procedure for determining the number of Apple Jacks in the container
 You have a smaller container and scale for reference
 The mass of the apple jacks = 230.1g

Data – your estimate

Data – the actual quantity!
 There are 682 apple jacks in the large container!

BRN – fill in the blanks #1-5
 When you buy eggs you usually ask for a (1)____________ eggs.
You know that one dozen of any item is (2)_________.
 Paper is not packaged by the dozen, it is packaged by the ream. A ream of paper has 500 sheets. Why is it useful to use units like a dozen or a ream? (3) ________________________
 What determines how many items should make up a particular unit? (4) ___________________________________________
 If you were asked to design a new unit to count something, what would you consider when choosing how many items should be included in your new counting unit?
(5) _______________________________________

When given the number of
KNIGHTS…
 _________________________________ by a
KNIGHT to find the number of items

When given the number of items…
 ________________________________ by a
KNIGHT to find the number of KNIGHTS

The mole…
 One MOLE of anything has
602,200,000,000,000,000,000,000 items.
 This number is called AVOGADRO’S NUMBER and is usually written in scientific notation as
6.022 x 10 23
 One MOLE of anything has 6.022 x 10 23 items

The mole
 When given the number of moles, we
______________________ by Avogadro’s number to find the number of items
 When given the number of items, we
_______________________ by Avogadro’s number to find the number of moles

Closure
 Here’s How: How do we determine the number of moles when given the number of particles?

Dimensional Analysis
 The factor-label method was developed to keep track of units in multi-step conversion problems (also known as dimensional analysis).
 In the method, equalities (i.e., conversion factors) are set up in fraction form. The equalities are then lined up sequentially and units used on the top and bottom of neighboring fractions are alternated so that units cancel.
 Crash Course

Dimensional Analysis
 For example, consider the conversion of inches to centimeters (1.00 in = 2.54 cm).
How many centimeters are in 5.00 inches?

Conversion Factors
= Sign

Dimensional Analysis

Dimensional Analysis
1. Determine what the question is asking you to solve for.
2. Determine what is given in the problem to be converted.
3. Identify and plug in the appropriate conversion factors as fractions (what is on top must also be on bottom).
4. Cancel units
5. Verify your answer. (Units must match units in step 1. If the answer doesn’t match, repeat 3 and 5).

Self-Motivated Practice
• For the next few months, we will be doing a lot of math and calculations.

Self-Motivated Practice
 YOU WILL NEED A CALCULATOR EVERY DAY!!!

Self-Motivated Practice
 The correct answer on these quizzes are worth very little.
 Therefore you will not get any credit (0/10) if you do not show your work (Factor- Labeling).
 Let me repeat this: A quiz with the correct answer but no work shown will get a score of
(0/10).
 Show and write out the work!

The MOLE
 KC 1: The mole (mol) is an SI base unit used to measure the amount of a substance.
 KC 2: 1 mole is equal to the number 6.02 x 10 23 particles.
 KC 3: Avogadro’s number is another name for the value of one mole, 6.02 x 10 23 .
 mole video

Avogadro
 In 1811 Avogadro hypothesized that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules
 Determining the number:
 If you divide the charge on a mole of electrons by the charge on a single electron you obtain a value of
Avogadro’s number of 6.02214154 x 10 23 particles per mole.

Counting Particles
There are three types of representative particle; atom, molecule, and formula units.
 The unit atom is used with single element.
 The unit molecule is used with covalently bonded element (2 non-metals).
 The unit formula units are used with ionicly bonded elements (1 metal and 1 nonmetal).

Practice
 KC 4: How many formula units of NaCl (sodium chloride) are in 43.4 moles?

Practice
 KC 5: How many moles of copper are there in
1.54 x 10 23 atoms of Cu?

Practice
 KC 6: Calculate the number of particles in 2.15 moles of iron.

How big is a mole?
 1 Mole of marbles would fill the entire Grand
Canyon and there would still be enough left over to displace all the water in Lake Michigan and a few other lakes!
 Computers can count at the rate of over 800 million counts per second. At this rate it would take a computer over 25 million years to count to
6.02 x 10 23

How big is a mole?
 A mole of hockey pucks would be equal to the mass of the Moon.
 Assuming that each human being has 60 trillion body cells (6.0 x 10 13 ) and the Earth's population is 6 billion (6 x 10 9 ), the total number of living human body cells on the Earth at the present time is 3.6 x 10 23 or a little over half of a mole.

Mass of a mole
 What does 1 Knight of skittles and 1 Knight of sprees have in common?
 What is different about a Knight of skittles and sprees?
 What does 1 mole of copper and 1 mole of carbon have in common?
 What is different about 1 mole of copper and 1 mole of carbon?
Think-Pair-Share WHY?

Mass of a mole
Chemical
Formula
Al
NaCl
MgO
MgSO
4
Moles of
Sample
1 mol
1 mol
1 mol
1 mol
Mass of
Sample
26.982g
58.443g
40.304g
120.366g
Molecular
Mass

Mass of a mole
 1 mol of copper and 1 mol of carbon have different masses because they have different numbers of protons, neutrons, & electrons

Mass of a mole
 Key Concept 7: A mole always contains the same number of particles; however, moles of different substances have different masses.

Chemical Formulas and the Mole
 Chemical formulas indicate the numbers and types of atoms contained in one unit of the compound
 One dozen molecules of CCl
2
F
2 contains 12 C atoms,
2(12) Cl atoms, and 2(12) F atoms.
 Similarly, one mole of CCl
2
F
2 contains one mole of C atoms, two moles of Cl atoms, and two moles of F atoms

Mass of a mole
 Key Concept 8 - Molecular Mass: (atomic mass, formula mass) of a molecule is its average mass as calculated by adding together the atomic weights of the atoms in the formula.
MM= Molecular Mass
Q= quantity
T= Total

MMQT - NaOH
MM
Na
O
H
Total =
Q T

Mass of a mole
 Key Concept 9 - Molar mass is the mass in grams of one mole of any pure substance.
 Key Concept 10 - The molar mass of any element is numerically equivalent to its molecular mass (atomic mass, formula mass) and has the units g/mol

Mass of a mole
 Key Concept 11: What is the molar mass of the following compounds?
 Potassium sulfate
 (NH
4
)
2
CO
3

Converting using moles
 Conversion factors so far…

Converting using moles
 Key Concept 12: How many grams of zinc are there in
1.5 moles of Zn?
 Key Concept 13: How many molecules of carbon dioxide are there 4.0g of carbon dioxide?

Converting using moles
 Key Concept 14: Gold (Au) is one of a group of metals called coinage metals (copper, silver, and gold). How many atoms of gold are in a
U.S. Eagle, a gold bullion coin with a mass of
31.1g Au?

Converting using moles
 Key Concept 15: The characteristic odor of garlic is due to allyl sulfate [(C the mass of 2.50 mol of (C
3
H
5
)
2
3
H
5
)
2
S ?
S]. What is

Converting using moles
 Key Concept 16: Aluminum chloride (AlCl
3
) is used in refining petroleum and manufacturing rubber and lubricants. A sample of aluminum chloride has a mass of 35.6g. How many formula units are present?

Percent Composition of an Oreo
 Obtain an Oreo. The cookie is made up of
WAFER and CREAMY FILLING.
 Using a balance, a plastic knife and a napkin
(to keep the cookie from directly touching the balance), calculate the percent of the cookie that is made up of each part.
 You have 15 minutes to complete and be ready to explain the process and your answer

Percent Composition of a
Compound
 KC 17: Mass percent composition – percent of total mass of a substance contributed by each element in the substance
 Found from comparing the mass of each element to the total mass of the substance

Percent Composition
 KC 18: Calculate the percent composition of water (H
2
O)

Percent Composition
 KC 19: Calculate the mass percent of oxygen in sodium sulfate.

Percent Composition
 KC 20: Calculate the percent composition of nitrogen in calcium nitrate

Empirical vs. Molecular Formula
 KC 21: Molecular formula – formula of the molecule as found in nature
 KC 22: Empirical formula – simplest ratio of atoms in a molecule
 Example –
C
6
H
12
O
6 vs.
CH
2
O

Empirical vs. Molecular Formula
 Circle the compounds that are given as empirical formulas:
 CaO
 Mg
2
(SO
4
)
2
 Be
2
S
2
 LiCl
 C
6
H
12
O
6

Formula Mass vs. Molecular Mass
 The formula mass (formula weight) of a molecule is the sum of the atomic weights of the atoms in its empirical formula
 KC 23: Formula mass = empirical formula
 The molecular mass (molecular weight) of a molecule is its average mass as calculated by adding together the atomic weights of the atoms in the molecular formula
 KC 24: Molecular mass = molecular formula
 Example –
C
6
H
12
O
6
180 g/mol vs.
CH
2
O
30 g/mol

Percent Composition and
Empirical Formula
 KC 25:
1.
Assume 100g of the sample. Use the percentages as your grams
2.
Convert the grams to moles for each element
3.
Divide each of the moles by the lowest number of moles present to get a whole number
4.
Round the number of moles as necessary or multiply each mole number by a fraction to get a whole number
5.
Use the whole numbers to write the empirical formula

Percent Composition and
Empirical Formula
 Given data on percent composition of a compound, you can find the empirical formula
 Example – Lactic acid is 40% carbon, 6.71% hydrogen, and 53.3% oxygen by mass.
Calculate the empirical formula.

Percent Composition and
Molecular Formula
 To determine the molecular formula from the empirical formula you need the molar mass
 KC 26: molar mass given in problem molar mass of empirical formula found
= whole number
 Example – Lactic acid has a molar mass of
90.08g/mol. Determine its molecular formula.

Practice
 KC 27: A compound is found to have 9.2% boron and 90.8% chlorine. Determine the empirical formula

Practice
 KC 28: A compound is shown to contain 50.1% sulfur and 49.9% oxygen. The molar mass of the compound is 128 g/mol. Determine the compound’s molecular formula.