Catalyst – May 6-4, 2011
Grab a calculator!
Monday Mystery Element!
1.
2.
3.
Used to make batteries
Can cause kidney
failure and high blood
pressure
Found in tobacco
leaves
Catalyst – May 6-4, 2011
Monday Mystery Element!
1.
2.
3.
Used to make
batteries
Can cause kidney
failure and high
blood pressure
Found in tobacco
Discovered by
leaves
Strohmeyer in CADMIUM!
1817…..it is……
Today’s Agenda
Catalyst
 Welcome to STOICHIOMETRY!!!
 Holy Moley!
 Moles – Particles/Particles – Moles
 Moles – Mass/Mass – Moles
 Work Time
 Exit Question
HOMEWORK: Stoichiometry Worksheet

Today’s Objectives
SWBAT perform mole – particle and
particle – mole calculations.
 SWBAT calculate the molar mass of
chemical substances.
 SWBAT perform mole-mass and
mass-mole calculations.

What is a mole to us chemists?

A benign overgrowth of cells because of a failure in
mitosis?
 NO!

But gross…
A rascly little rodent?
 NOOOO!

A TV show featuring celebrities?
 NOOOOO!

Then WHAT IS IT?????!!!???!?!?!???!!!!
The Mole
Think of the term “a dozen”…
How many donuts
are in a dozen?
How many eggs
are in a dozen?
The Mole
Just like a dozen refers to 12 objects…
The mole refers to…
6.02 x
23
10
particles
Avogadro’s Number
This number is called Avogadro’s
number…
6.02 x
23
10
EQUALS
602,000,000,000,000,000,000,000
http://molechemistry.info/
Avogadro’s Number
Key Point #1:
1 mole (mol) =
6.02 x
23
10
atoms OR molecules
Stoichiometry Calculations Part One
Moles – Particles
and
Particles – Moles
(Particles = Atoms or
Molecules)
Avogadro LOVES Us!

Key Point #2: Avogadro's
number (6.02 x 1023) is used to
convert between moles and
particles (atoms/molecules).
 It
all relates back to the mole…
 Guess what’s coming back…
TRAIN TRACKS!!!

Step 1:
 What

Step 2:
 Write

to what?
conversion factor(s)
Step 3:
 Train
tracks
Avogadro’s Number: Example #1
Write this down!!!
How many atoms of Na are in
3.4 moles Na?
Scientific Notation on the Calculator

Don’t forget! When you need to
type in a scientific notation
23
number like 6.02 x 10 …
Type 6.02 EE 23 instead
SAVE TIME AND LOOK COOL!
Avogadro’s Number: Example #2
Write this down!!!
How many moles of N2 are in
250 molecules N2?
Avogadro’s Number: You Try!
How many molecules of
C12H22O11 are in 2.1
moles of C12H22O11?
Stoichiometry Calculations Part Two
Moles – Mass
and
Mass – Moles
OOOH, I want some more train tracks!

Key Point #3: Molar mass is
the number of grams in one
mole of a substance. It is used
to convert between moles and
mass.
 But
Ms. Stroh, how am I ever going to find out
this information?
Molar Mass: Example #1
“What is the molar mass?” means…
“How many grams are in one mole of a
substance?”
1 mol C = 12.01 g C
Molar Mass: Example #2
Write this down!!!
1 mol Na = 22.99 g Na
Molar Mass: Example #3
Write this down!!!
1 mol CO2 = 44.01 g CO2
Molar Mass: You Try!
1 mol KNO3 = 101.1 g KNO3
Molar Mass: Step-Up Problem #1
Write this down!!!
If we have 3.5 moles of KNO3, how
many grams of KNO3 would we have?
Molar Mass: Step-Up Problem #2
Write this down!!!
If we have 20 grams CH4, how
many moles of CH4 do we have?
Independent Practice
Worksheet time! Show your
work!
Finish for Homework!
Show Train Tracks on #7-14

Exit Question
How many molecules are in 1
mole of NH4?
2. How many grams are in 2.3 moles
of NH4
HW: Finish Worksheet and read 12.1
and 12.2 in book!
1.