1. The Mole

2. Measuring Matter
How can you quantify the amount of sand in this sand castle?
Chemists measure the amount of a substance
using a unit called the mole.

3. What is the mole?
A mole is the amount of substance that contains the same number of atoms as 12 grams of Carbon-12.
It is a counting unit just like a dozen.
A dozen = 12 somethings
A couple = 2 somethings
A mole = 6.02 x 1023 somethings

4. What is the Mole? 6.02 x 1023 is called “Avogadro’s Number”
because Amedeo Avogadro discovered it.
1 mole of any element has a mass (in grams) equal to its average atomic mass.
Substance
Representative particle
Chemical formula
Representative particles in 1.00 mol
Copper
Atom Cu
6.02  1023
Atomic nitrogen N
Nitrogen gas
Molecule N2
Water
H20
Calcium ion
Ion
Ca2+
Calcium fluoride
Formula unit
CaF2

5. Examples 1 mole of helium has a mass of 4.00 grams.
How many atoms of helium is that?
1 mole of sodium is grams.
How many atoms is that?
1 mole of oxygen has a mass of 16 grams.
How many atoms of oxygen is that?
1 mole of potassium has a mass of ____ g.

7. Molar Mass
When we write out the average atomic mass in “grams” we call this the molar mass – it is literally the mass of one mole. What is the molar mass of fluorine? What is the molar mass of iron? What is the average atomic mass of iron?

8. Molar Mass in grams of that element
Molar conversions
mole of any substance
equals
6.02 x 1023 atoms of that element
Molar Mass in grams of that element

9. To do a molar conversion problem:
*Do dimensional analysis.*
Put what you know over 1.
Bring that unit down and over.
Put the unit you want on top.
Fill in the numbers.
*Put a “1” in front of moles in a conversion*
*Put “6.02 x 1023” in front of atoms in a conversion*
*Put the molar mass in front of grams in a conversion*

10. 1. How many atoms are in 6 moles of carbon?

11. 2. How many moles are in 5.26 x 1024 atoms of nitrogen?

12. 3. How many atoms are in 55.4 grams of lithium?

13. How many atoms are in 55.4 grams of lithium?

14. How many atoms are in 55.4 grams of lithium?

15. How many atoms are in 55.4 grams of lithium?

16. How many atoms are in 55.4 grams of lithium?

17. How many atoms are in 55.4 grams of lithium?

18. How many atoms are in 55.4 grams of lithium?

19. How many atoms are in 55.4 grams of lithium?

20. How many atoms are in 55.4 grams of lithium?

21. How many atoms are in 55.4 grams of lithium?

22. 4. What is the mass in grams of 7.00 moles of iron?

23. What is the mass in grams of 7.00 moles of iron?

24. 5. What is the mass in grams of 3.011 x 1023 atoms of iron?

25. What is the mass in grams of 3.011 x 1023 atoms of iron?

26. 6. What is the number of moles in 3.011 x 1023 atoms of magnesium?

27. What is the number of moles in 3.011 x 1023 atoms of magnesium?

28. 7. How many atoms are in 8.43 moles of nickel?

29. How many atoms are in 8.43 moles of nickel?

30. 8. How many atoms are in 1.00 x 10-10 grams of gold?

31. How many atoms are in 1.00 x 10-10 grams of gold?