• A counting unit similar to a dozen, except instead of 12, it’s 602 billion trillion
• 602,000,000,000,000,000,000,000
• 6.02 X 10 23 (in scientific notation)
• This number is named in honor of Amedeo
Avogadro (1776 – 1856), and is called
Avogadro’s Number .

•
1 mole of cookies = 6.02 x 10 23 cookies
•
1 mole of cars = 6.02 x 10 23 cars
•
1 mole of Al = 6.02 x 10 23 ?
•
1 mole of Al = 6.02 x 10 23 Al atoms
•
1 mole of water = ?
•
1 mole of H
2
O = 6.02 x 10 23 H
2
O molecules

How big is a mole?
• How many cents are in one mole of pennies?

How big is a mole?
• How many cents are in one mole of pennies?
6.02 x 10 23 ¢

How big is a mole?
• How many dollars are in 6.02 x 10 23 ¢?

How big is a mole?
• How many dollars are in 6.02 x 10 23 ¢?
6.02 x 10 23 ¢ $1
100¢
= $6.02 x 10 21

How big is a mole?
• There are about 7.0 billion (7.0 x 10 9 ) people on earth.
• If we divided the 1 mole of pennies ($6.02 x 10 21 ) equally among all the people on earth how many dollars would you have?

How big is a mole?
• There are about 7.0 billion (7.0 x 10 9 ) people on earth.
• If we divided the 1 mole of pennies ($6.02 x 10 21 ) equally among all the people on earth how many dollars would you have?
$6.02 x 10 21
7.0 x 10 9 people
= $8.6 x 10 11 /person
$860,000,000,000 = 860 billion dollars

How big is a mole?
• How many years would it take you to spend your 860 billion dollars ($8.6 x 10 11 ) if you spent
$94,000 per day?

How big is a mole?
• How many years would it take you to spend your 910 billion dollars if you spent $100,000 per day?
$8.6 x 10 11 day
$94,000 year
365 days
= 25,000 years

Neanderthals died out about 25,000 years ago

“Mollionaire”

The thickness of one page in your chemistry notebook is about 0.0065 cm. How many meters is this?

What is the thickness of one page in your chemistry notebook in meters?
0.0065 cm
0.01 m cm
= 0.000065 m

How many meters high would a stack of one mole of pages be?

How many meters high would a stack of one mole of pages be?
6.02 x 10 23 pages 0.000065 m page
= 3.9 x 10 19 m

The distance to the moon is 380,000,000m. If you took your stack of papers from problem 6 and broke it down into smaller stacks, how many stacks of papers could you make from the earth to the moon?

The distance to the moon is 380,000,000m. If you took the 3.9 x 10 19 m stack of papers, how many stacks of papers could be made from the earth to the moon?
3.9 x 10 19 m stack
380,000,000 m
= 1.0 x 10 11 stacks
1.0 x 10 11 stacks = 100,000,000,000 stacks

1 mole of pages would be enough to build 100 billion stacks of paper to the moon.

When using atomic masses make sure to round to at least one decimal place.

What is the atomic mass of actinium (Ac)?
227.0278
227.0

What is the atomic mass of hydrogen (H)?
1.00794
1.0

What is the mass of hydrogen (H
2
)?
2.0

Vitamin A: C
20
H
30
O
The first of the 13 vitamins to be discovered, it plays a vital role in the growth and repair of body tissues, and is particularly important in maintaining good eyesight and healthy skin, as well as aiding in bone and teeth formation.
Vitamin A-rich foods include: Liver, sweet potatoes, carrots, mangoes, spinach, cantaloupe, dried apricots, milk, egg yolks, mozarella cheese.

Determine the
Molecular Mass of
Vitamin A
C
20
H
30
O

Determine the
Molecular Mass of
Vitamin A
C
20
H
30
O
20 x 12.0 = 240.0
30 x 1.0
= 30.0
1 x 16.0 = 16.0
= 286.0 amu

H H
2
O NaCl
•
H is an atom and it would therefore have an atomic mass.
•
H
2
O is a molecule and it would therefore have a molecular mass.
•
NaCl is neither an atom or a molecule and would therefore have a formula mass.

Formula Mass
• The formula mass is the mass of an ionic compound.
• An ionic compound is formed from a combination of metals and nonmetals.
• Formula masses are calculated the same as molecular masses.

Determine the
Formula Mass of
Calcium Phosphate
Ca
3
(PO
4
)
2
3 x 40.1 = 120.3
2 x 31.0 = 62.0
8 x 16.0 = 128.0
= 310.3 amu

Homework
• Molecular and Formula Mass Worksheet.
• Don’t forget to show your work on your calculations.