C: 2 Nov. 2010
Objective: SWBAT show what you know
about the language of chemistry on a test,
and convert between atoms/molecules
and moles of an element.
 Do now: What type of question are you
most confident about?
 What type of question are you least
confident about?

C: Agenda
Do now
II.
Test! Language of Chemistry
III.
The Mole – notes
IV.
Converting between moles and number of
atoms and moles and mass
V.
Practice Problems
Homework: Week 9 Homework: #1-26: Weds.
Bring your calculator EVERY day!! 
Calculator check = 10 point quiz tomorrow!
I.
A: 2 November 2010
Take Out Homework: Week 8 Test
Review
 Objective: SWBAT show what you know
about the language of chemistry on a test.
 Do now (in your notebook): What type
of question are you most confident about?
 What type of question are you least
confident about?

A: Agenda
Do now
II.
Test! Language of Chemistry
Homework: Bring a calculator EVERY day!
Calculator check = 10 point quiz tomorrow!
I.
Test
The periodic table is on the last page.
 You can rip it off if you’d like.
 When you are finished, turn your test over
on your desk.
 Work on something silently
 Missed work for chem, work for another
class, read a book, etc…
 Remain silent, even if you are finished!

A: 3 Nov. 2010
Take out your calculator!
 Objective: SWBAT convert between
atoms/molecules and moles and mass of
an element.
 Do now: (In your notebook) We buy eggs
by the dozen, and shoes by the pair.
Name at least two other things that you
buy in multiples (that is, more than one at
a time).

Agenda
Do now, calculator check
II. Notes on the Mole, converting between
moles and number of atoms/particles
III. Practice Problems
IV. Converting between moles and mass of
elements
V. Practice Problems
Homework: Week 9 Homework #1-34 odds:
Thurs.
I.
Announcement
I’m going to underline the things you
should write down.
 If it’s not underlined, don’t write it down.

New Unit: Stoichiometry
 The calculation of the amounts of matter
used in a chemical reaction and produced
by a chemical reaction.
 H2(g) + O2(g)  H2O(g)
 If 5 grams of hydrogen is reacted with 5
grams of oxygen, how many grams of
water will be formed? Will any hydrogen
or oxygen be left over? How much?

The Mole
Atoms are so tiny; how do we quantify
their masses?
 We communicate the mass of atoms in
terms of really, really huge groups of
atoms.
 6.02x1023 atoms, to be exact!

The Mole
Mole: The scientific unit for amount of
substance
23 atoms or molecules
 =6.02x10
 =Avogadro’s Number

How big is a mole?
Enough soft drink cans to cover the surface of
the earth to a depth of over 200 miles.
 If you had Avogadro's number of unpopped
popcorn kernels, and spread them across the
United States of America, the country would
be covered in popcorn to a depth of over 9
miles.
 If we were able to count atoms at the rate of 10
million per second, it would take about 2
billion years to count the atoms in one mole.

Really? How big?
1 mole of pennies could be distributed to
all the currently-living people of the world
so that they could spend a million dollars
per hour every hour (day and night) for
the rest of their lives.
 1 mole of blood cells would be more than
the total number of blood cells found in
every human on earth.

Amadeo Avogadro
Italian
 Born: 1776
 Studied physics and
math
 Taught high school,
then college

Converting between moles and
atoms/molecules

Two possible conversion fractions
1mole
6 . 02 x10
23
6 . 02 x10
atoms / molecules
Same two
fractions for
ANY element
or
compound!!
23
atoms / molecules
1mole
Example 1

How many moles are equal to 3.50x1023
atoms of silver?
Example 2

How many moles are equal to 1.25x1024
molecules of sodium bromide?
Example 3

How many atoms are there in 1.50 moles
of sulfur?
Example 4

How many molecules are there in 10.55
moles of water?
1.
2.
3.
4.
How many moles of silver are equal to
3.01 x 1023 atoms of silver?
How many moles of water are equal to 2500
molecules of water?
How many atoms of carbon are in 3.2 moles
of carbon?
How many molecules of calcium chloride are
in 1.0 mole of calcium chloride?
C: 8 November 2010
Take Out Homework: Week 9 #1-18
and your calculator!
 Objective: SWBAT convert between
atoms, moles and mass of elements.
 Do now: Choose and write the correct
fraction to convert if…
 a. The problem gives you atoms and asks
for moles.
 b. The problem gives you moles and asks
for atoms.

Agenda
Do now, calculator check
II. Homework answers
III. Convert between moles and mass of
elements
IV. Convert between atoms, moles, and mass
of elements
Homework: Week 9 Homework #19-34:
Weds.
I.
Converting between moles and
mass of elements

Two possible conversion fractions:
1mole
atomic _ mass ( g )
atomic _ mass ( g )
1mole
Example 1

Calculate the mass in grams of 3.50 moles
of hydrogen.
Example 2

Calculate the number of moles equal to
10.0 grams of silicon.
1.
2.
3.
4.
What is the mass in grams of 3.50 mol of
copper?
What is the mass in grams of 2.25 mol of iron?
How many moles of aluminum are equal to
11.9 grams of Aluminum?
How many moles of calcium are equal to 5.00
grams of calcium?
A: 4 Nov. 2010
Take Out Homework: Week 9
Homework #1-26 odds
 Objective: SWBAT convert from mass to
moles to atoms and calculate molar mass.
 Do now:
a. Calculate the number of moles equal to
5.00x1025 atoms of gold.
b. Calculate the mass of 5.00 moles of gold.

Agenda
Do now
II. Homework check
III. Mass to moles to atoms examples and
problems
IV. Calculating molar mass examples and
problems
Homework: Week 9 Homework #27-38:
Mon.
I.
Mass to moles to atoms
Ex 1: Calculate the mass of 8.00x1023
atoms of gold.
 Ex 2: Calculate the number of atoms in
5.00 grams of bromine.

1.
2.
3.
4.
Calculate the mass of 3.01x1025 atoms of
copper.
Calculate the number of atoms in 10.0
grams of lithium.
Calculate the mass of 5000. atoms of
zinc.
Calculate the number of atoms in 1.000
grams of beryllium.
C: Homework
Week 9 Homework #19-34: Weds.
 Bring calculator every day!

A: 8 Nov. 2010
Take Out Homework: Week 9 #27-34
 Objective: SWBAT convert between
mass, moles and number of atoms of an
element
 Do now: (In your notebook) Calculate the
mass of 500. atoms of cobalt.

Agenda
Do now
II. Homework check
III. Using the electronic balance
IV. Mass to moles to atoms stations
Homework: Fix Week 9 #1-34
Hand in missing work!
I.
Using an electronic balance
Press “on”
 If the display does not read “0.00,” press
“zero.”
 Gently place the item to be massed on the
metal plate.
 Record the mass with TWO decimal places
(ex: 4.50 g).

Using an electronic balance
Treat these balances with extreme care!
 They cost about $250 each.
 Never place anything directly on the metal
plate, including your fingers!
 Press buttons gently.
 Never push or pull on any part of the
balance.
 If a problem occurs, let me know
immediately.

Mass to moles to atoms lab

On the front:
 Find the mass of the sample. Subtract
the mass of the container (given on the
card).
 Convert to moles
 Convert to number of atoms

On the back:
 Copy down the number of atoms (from
the card)
 Convert to moles
 Convert to mass
 Check your answer by massing the
sample on the balance.
Homework
Week 9 Homework: Check #1-34
 Mass, moles, atoms lab: Finish, check for
units and element symbols
 Due tomorrow
 Late work due by 3:15 today!!

Do your best!
Work carefully and quickly!!
 Low grades result from sloppy work, not
showing work, not writing down units and
wasting time during labs.
 This is a 1st quarter grade!
 5 min. per station.

Homework

Check and fix Week 9 Homework #1-34
C: Homework

Week 9 Homework #19-34

How do you convert between moles and
mass of a compound?!
Calculating Molar Mass
The mass of one mole of a compound.
 Units: g/mol
 Example 1: NaCl
 Example 2: CO2
 Example 3: C8H10N4O2 (caffeine!)

Calculate the molar mass…
1.
2.
3.
lithium bromide
aluminum carbonate
acetic acid (CH3COOH, the acid in
vinegar)
A: Homework
Week 9 Homework #27-34: Mon.
 Bring your calculator every day!

Converting between moles and
mass of compounds
Example 1
 Calculate the mass of 4.52 moles of
lithium bromide.

Example 2

Calculate the number of moles equal to
1.00 grams of aluminum carbonate.
Example 3

Calculate the mass of 0.500 moles of
acetic acid.
1.
2.
3.
Calculate the mass of 20.0 moles of
lithium bromide.
Calculate the number of moles equal to
100.0 grams of aluminum carbonate.
Calculate the mass of 0.400 moles of
acetic acid.
Mass to moles to molecules
Ex. 1: Calculate the mass of 12,000.
molecules of lithium bromide.
Ex. 2: Calculate the number of molecules of
aluminum carbonate in 100 grams of the
compound.
1.
2.
3.
4.
Calculate the mass of 3.00x1020 molecules
of lithium bromide.
Calculate the number of molecules of
aluminum carbonate in 45.0 grams of the
compound.
Calculate the mass of 1,200.0 molecules of
acetic acid.
Calculate the number of molecules of acetic
acid in 10.0 grams of the compound.

Homework: Week 9 Homework #
MOLES CONVERSIONS
STATIONS
Directions

When you receive a sample, find the
correct box on your worksheet.
Instructions

Front side:
 A. Find the mass of the sample (subtract
the mass of the container)
 B. Convert the mass to moles.
 C. Convert the moles to number of
atoms or molecules.

Back side:
 A. Record the number of atoms or
molecules on the card.
 B. Convert that to moles.
 C. Convert moles to mass (grams).
 D. Find the mass of the sample
(subtract the mass of the container), and
compare to your calculated mass.
Work quickly. 7 minutes per station!
 Pass the sample and card to the next table
when the timer goes off.
 Due at the end of the period.

Practice Moles to Number of Atoms
Conversions
1.
2.
3.
4.
How many moles of vanadium are in 4.5
x 102 atoms of V?
How many moles of oxygen gas are in
45,000 molecules of O2?
How many moles of neon are in 1.2 x 103
atoms of Ne?
How many moles of chromium are in
7.90 x 1021 atoms of Cr?
Atoms to Moles
How many atoms of sodium are in 0.5
moles of sodium?
 How many atoms of oxygen are in 1.5
moles of oxygen?
 How many atoms of fluorine are in 0.075
moles of fluorine?
 How many atoms of argon are in 3.45
moles of argon?

Converting between mass (g) and
moles (mol)
1 mol O
15.999 g O
 Or
15.999 g O
1 mol O
 Choose one depending on if you are given
grams of oxygen or moles of oxygen.
Lithium (Li)
 Calculate the mass of 3.0 moles of lithium.
 How many atoms are there in 3.0 moles of
lithium?

Chromium (Cr)
 Calculate the number of moles of
chromium if you had 3.25x1034 atoms of
chromium.
 Calculate the mass of 3.25x1034 atoms of
chromium.

Zinc (Zn)
 How many moles of zinc are there in 34.7
grams of zinc?
 How many atoms of zinc in 34.7 grams?

Write both fractions.
Germanium (Ge)
 Calculate the mass of 3.0 moles of
germanium.
 How many atoms is that?

Which Fraction?

How many moles of chlorine are in 6.4
grams of chlorine?
Which Fraction?
How many grams of krypton are in
8.9x1012 moles of krypton?
 How many atoms is that?

Which Fraction?
How many grams of hydrogen are in 32.1
atoms of hydrogen?
 How many moles is that?

Which Fraction?

How many moles of aluminum are in 6.5
grams of aluminum?
Which Fraction?
What is the mass of 5.6x103 moles of
mercury?
 How many atoms is that?

Write both fractions.
How many moles are equal to 2.58x1067
atoms of Xenon (Xe)?
 Calculate the mass.

Which Fraction?
How many moles of Xe are in 9.0 grams of
Xe?
 How many atoms is that?

Molar Mass Practice
1.
2.
3.
4.
5.
What is the mass in grams of 3.50 mol of
copper (Cu)?
What is the mass in grams of 2.25 mol of iron
(Fe)?
What is the mass in grams of 0.375 mol of
potassium (K)?
What is the mass in grams of 0.0135 mol of
sodium (Na)?
What is the mass in grams of 16.3 mol of
nickel (Ni)?
How many moles of Aluminum are in 11.9
grams of Aluminum?
 How many moles of calcium (Ca) are in
5.00 grams of calcium?
 How many moles of copper (Cu) are in
13.3 grams of Copper?
 How many moles of gold (Au) are in 3.60
x 10-10 grams of gold?

Mass to atoms
1.
2.
3.
4.
What is the mass in grams of 1.20 x 108
atoms of copper?
What is the mass in grams of 7.5 x 1015
atoms of nickel?
How many atoms of sulfur are in 4.00
grams of sulfur?
How many atoms of carbon are in 1500
grams of carbon?