1. What is a mole? Mole Conversion Problems

2. Maybe! What is a mole? But not really in chemistry!
A furry, burrowing woodland creature, revered by many and adored by all?
Maybe!
But not really in chemistry!

3. A Mole...
is a unit of measurement that tells how many particles of something you have!

4. much like a dozen (12), a gross (144) or a ream (500) is just a unit that groups smaller numbers into big ones...but its a big one; a REALLY big one!

5. (that’s a lot of flowers!)
1 mole = 6.02 x 1023 particles!
(that’s a lot of flowers!)

6. Atoms, molecules, or formula units. What are particles?
Particles could be anything, but because of the size of the number, we usually mean
Atoms,
molecules, or
formula units.

7. Avogadro’s Number The number 6.02 x 1023 is called Avogadro’s number.
This is due to Amadeo Avagadro’s research leading to the discovery, not the discovery of the number itself.
It is a little known fact that Avogadro was voted his class’s most likely to have a scientific discovery and most likely to look really creepy.

8. Practice Problem #1
How many moles are in 2.57 x 1025 atoms He?

9. Practice Problem #2
How many molecules of CO2 are in 25.3 moles?

10. Moles and Volume
It has also been discovered that 1 mole of all gases at a certain set of conditions called STP (standard temperature and pressure) have the same volume—22.4L!
So, 1 mole = 22.4L STP)

11. Practice Problem #3
How many moles of O2 are in 29.3L of O2 gas?

12. Practice Problem #4
If you have 3.6 moles of N2O (Nitrous oxide) how many liters would you have?

13. NOT by counting the number of particles!
Mass and Moles
How do we usually measure out chemicals in a lab?
NOT by counting the number of particles!

14. Mass and Moles We usually use mass to measure out chemicals.
The problem with mass
is that not all atoms or
compounds have the same mass.

15. Mass and Moles
The atomic mass on the periodic table is also an element’s molar mass (the mass of one mole of an element, measured in g/mol).

16. What is the molar mass of...Al Ba Rn

17. Furthermore...
Since compounds are just atoms bonded together, you can find the molar mass of a compound by adding together the molar mass of all the elements in the compound.

18. What is the molar mass of...
NaCl
CO2
Be3N2
Ca(NO3)2

19. Practice Problem #5
How many grams of iron are in 3.5 moles?

20. Practice Problem #6
How many moles of Na2O are in 355.1g?

21. Two Step Problems
We have now discussed moles in three ways—as particles (1 mol = 6.02x1023 particles), as a mass ( molar mass = 1 mol) and as a volume (22.4 L = 1 mol)
To get from particles to grams, grams to liters or particles to liters of a substance, two steps are required, with moles always in between!