Today’s Agenda
Catalyst
 Holy Moley!
 Molar Conversions

 Representative
 Molar
Particles
Mass
Work Time
 Exit Question

HOMEWORK:
Today’s Objectives
SWBAT define the mole,
representative particles, and
Avogadro’s number.
 SWBAT use Avogadro’s number and
molar mass to complete molar
conversions.

LESSON TITLE:
MOLES AND MOLAR
CONVERSIONS
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?????!!!???!?!?!???!!!!
Measuring Matter

Remember! Chemistry is a
quantitative science that requires
you to measure amounts of matter.
Units to Count Matter
Think of the term “a dozen”…
How many donuts
are in a dozen?
How many eggs
are in a dozen?
Avogadro’s Number
Just like a dozen refers to 12 objects…
The mole refers to…
6.02 x
23
10
REPRESENTATIVE PARTICLES
602,000,000,000,000,000,000,000
What is a mole to us chemists?

Key Point#1: Chemists use a unit
called the mole to measure matter.
1
mole ALWAYS equals…
Molar Mass OR Avogadro’s number
Molar Mass = the grams in 1 mole
Avogadro’s Number = 6.02 x 1023
Moles – Mass

Key Point #2: Molar mass is
used to convert between moles
and mass.
Mole – Mass Example

Tungsten is a rare metal that is found
naturally on Earth only in chemical
compounds. If it was isolated, how many
grams would be in 3.4 moles of tungsten
(W)?
Moles – Particles

Key Point #3: Avogadro's
number (6.02 x 1023) is used to
convert between moles and
representative particles (atoms,
formula units, molecules).
 It
all relates back to the mole…
 Guess what’s coming back…
More on Representative Particles
Substance
Chemical
Formula
Representative
Particle
Representative
Particles in
1 Mole
Copper
Cu
Atom
6.02 x 1023
Atomic Nitrogen
N
Atom
6.02 x 1023
Elemental
Nitrogen
Water
N2
Molecule
6.02 x 1023
H2O
Molecule
6.02 x 1023
Sucrose
C12H22O11
Molecule
6.02 x 1023
Calcium Ion
Ca2+
Ion
6.02 x 1023
Calcium Fluoride
CaF2
Formula Unit
6.02 x 1023
Mole – Particle Example

Titanium is a strong metal that is corrosionresistant. Because it is biocompatible, it is
used in a gamut of medical applications
including surgical implants like hip balls and
sockets. Titanium is often alloyed with
aluminum and vanadium. How many moles
are equal to 4.5x1023 atoms of titanium (Ti)?
TRAIN TRACKS!!!

Step 1:
 What

Step 2:
 Write

to what?
conversion factor(s)
Step 3:
 Train
tracks
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 E 23 instead
SAVE TIME AND LOOK COOL!
You try!
Potassium chloride has a crystalline structure
like many other ionic salts. How many moles
are equal to 3.61x1024 representative
particles of potassium chloride (KCl)?
 Info from Avogadro...
 1 mol KCl = 6.02x1023 rep. particles KCl
 1 mol KCl = 6.02x1023 formula units KCl

You try!
Sucrose, C12H22O11, is also known as saccharose.
If you have 2.1 moles of sucrose, how many
molecules of sucrose do you have?
 Info from Avogadro...

1
mol C12H22O11 = 6.02x1023 molecules C12H22O11
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!
 Turn into
folder when
done!

Exit Question
1.
2.
What information do we get from
Avogadro?
What is the molar mass of Helium?
HW: 1st Page of Worksheet
(front and back)