1. Molar Mass Page 58 The mass, in grams, of 1 mole
Equal to the mass on the periodic table
1 mole of C atoms =
1 mole of Mg atoms =
1 mole of Cu atoms =
12.0 g
24.3 g
63.5 g

2. Other Names Related to Molar Mass
Molecular Mass/Molecular Weight
Formula Mass/Formula Weight
Gram Atomic Mass/Molecular Mass
THE POINT: You may see all these terms which mean the SAME THING!

3. Molar Mass of Molecules and Compounds (page 58)
Add up the masses of each element
1 mole of NaCl
1 mole of Na = 23.0 g
1 mole of Cl = 35.5 g
1 mole of H2O
1 mole of H x 2 = 1.0 g x 2 = 2.0 g
1 mole of O = 16.0 g
= 58.5 g
= 18.0 g

4. 94.2 g 78.0 g Learning Check! Page 57 Molar Mass of K2O = ?
B. Molar Mass of antacid Al(OH)3 = ?
94.2 g
78.0 g

5. Learning Check page 57
Prozac, C17H18F3NO, is a widely used antidepressant that inhibits the uptake of serotonin by the brain. Find its molar mass.
309 g

6. The Mole
To play the movies and simulations included, view the presentation in Slide Show Mode.

7. The Mole A counting unit
Similar to a dozen, but instead of 12, it’s 602 billion trillion 602,000,000,000,000,000,000,000
6.02 X 1023 (in scientific notation) 6.02E23 on your TI calculator
This number is named in honor of Amedeo Avagadro (1776 – 1856) Avagadro’s Number

8. Just 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.

9. Learning Check
Suppose we invented a new collection unit called a rapp. One rapp contains 8 objects.
1. How many paper clips in 1 rapp?
a) 1 b) 4 c) 8
2. How many oranges in 2.0 rapp?
a) 4 b) 8 c) 16
3. How many rapps contain 40 gummy bears?
a) 5 b) 10 c) 20

10. A Mole of Particles Contains 6.02 x 1023 particles
= x 1023 C atoms
= x 1023 H2O molecules
= x 1023 NaCl “molecules”
(technically, ionics are compounds not molecules so they are called formula units)
6.02 x 1023 Na+ ions and
6.02 x 1023 Cl– ions
1 mole C
1 mole H2O
1 mole NaCl

11. Avogadro’s Number as Conversion Factor
6.02 x 1023 particles
1 mole or
1 mole
Note that a particle could be an atom OR a molecule!

12. Solving Mole Problems with Dimensional Analysis
Start with given information
Set up conversion factor so unwanted labels cancel out
Multiply across the top
Divide by what’s on the bottom

13. Learning Check = 2.99 mol S 1. Number of atoms in 0.500 mole of Al
2.Number of moles of S in 1.8 x 1024 S atoms
0.500 mol Al
6.02 x 1023 atoms
1 mol Al
= x atoms
1.8 x 1024 S atoms
1 mol S
6.02 x 1023 atoms =
2.99 mol S

14. Calculations with Molar Mass
Grams Moles

15. Converting Moles and Grams
Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al?
3.00 mol Al
27.0 g Al
1 mol Al
= 81.0 g

16. 0.765 mol aspartame Learning Check!
The artificial sweetener aspartame (Nutra-Sweet) formula C14H18N2O5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame?
0.765 mol aspartame

17. Everything must go through Moles!!!
Calculations
molar mass Avogadro’s number Grams Moles particles
Everything must go through Moles!!!

18. Atoms/Molecules and Grams
How many atoms of Cu are present in 35.4 g of Cu?
35.4 g Cu mol Cu X 1023 atoms Cu g Cu mol Cu
= 3.4 X 1023 atoms Cu

19. 1.21 x 1024 atoms K Learning Check!
How many atoms of K are present in 78.4 g of K?
1.21 x 1024 atoms K

20. 359 g glucose Learning Check!
What is the mass (in grams) of 1.20 x 1024 molecules of glucose (C6H12O6)?
359 g glucose

21. = 2.94 x 1024 atoms O Learning Check!
How many atoms of O are present in 78.1 g of oxygen?
78.1 g O2 1 mol O X 1023 molecules O2 2 atoms O g O mol O molecule O2
= 2.94 x 1024 atoms O

22. What questions do you have?