1. The Mole
Chapter 11

2. Measuring Matter
Section 11.1

3. How much is a mole?
Count large # of items is easier when you use counting units like the dozen
Chemists use a counting unit called the mole

4. How is a mole used in chemistry?
Mole (mol) is SI base unit used to measure amount of substance
1 mole = Avogadro’s # = x 1023 RP
Representative particles (RP)
= atoms
= molecules
= FU
= electrons
= ions

5. Relate a mole to common counting units
1 dozen eggs = 12 eggs
1 pair of shoes = 2 shoes
1 ream of paper = 500 sheets of paper
1 lb of sugar = 16 ounces of sugar
1 Liter of HCl = 1000 mL of HCl

6. 1 Mole of Representative Particle (RP)
Molecule of water
Atom of Cu
FU of NaCl

7. How many roses are in 3 ½ dozens?
Conversion factor: 12 roses/1 dozen
3.5 dozen x 12 roses/1 dozen = 42 roses

8. Convert moles  # RP
? RP = given moles x 6.02 x 1023 RP
1 mole

9. Example ? mole = given RP x 1 mole 6.02 x 1023 RP
= 2.65 x 1024 FU ZnCl2 x 1 mole ZnCl2
6.02 x 1023 FU ZnCl2
= 4.40 moles ZnCl2

10. Convert # RP  moles
? mole = given RP x 1 mole
6.02 x RP

11. Conversion factor: 6.02 x 1023 RP/ 1 mol
Example
Conversion factor: 6.02 x 1023 RP/ 1 mol
? RP = given moles x 6.02 x RP
1 mole
= 3.5 moles sucrose x 6.02 x 1023 molecules sucrose
1 mole sucrose
=2.11 x 1024 molecules sucrose

12. Practice Determine the # of atoms in 2.50 mol Zn. 1.51 x 1024 atoms Zn
Given 3.25 mol AgNO3, determine # FU
1.96 x 1024 formula units AgNO3
Calculate # molecules in 11.5 mol H2O
6.92 x 1024 molecules H2O

13. More Practice How many moles contain 5.75 x 1024 atoms of Al?
9.55 mol Al
How many moles contain 3.75 x 1024 molecules CO2?
6.23 mol CO2
How many moles contain 3.58 x 1023 formula units ZnCl2?
0.595 mol ZnCl2

14. Homework
p from textbook
1-4 10
Due tomorrow

15. Mass and the Mole
Section 11.2

16. Relate the mass of an atom to the mass of a mole of atoms
1 dozen eggs and 1 dozen limes are not equal masses
Why? Because they are different compositions and size

17. Avogadro’s Number 6.022 x 1024 Representative Particles
ions,
atoms,
molecules,
electrons, FU
Lorenzo Romano Amedeo Carlo Avogadro, conte di Quaregna e di Cerreto
( ) Photo from

18. Mole to Atom? 1 mole = 6.022 x 1024 atoms
1 mole = x 1024 molecules
1 mole = x 1024 ions
1 mole = x 1024 electrons
1 mole = x 1024 Formula Units (FU)

19. Calculate mole  grams
? Grams = given moles x grams from PT
1 mole

20. Calculate the mass of an element when given # of atoms of element
? grams = atoms x 1 mol x g from PT
6.02 x 1023atoms mol

21. Calculate # of atoms of element when given mass of element
? Atoms = grams x 1 mol x 6.02 x 1023atoms
g from PT mol

22. Homework
Pages (12-14) from the textbook
Due tomorrow

23. Moles of Compounds
Section 11.3

24. Recognize the mole relationship shown by a chemical formula

25. Calculate the molar mass of a compound
Add the atomic masses from the periodic table together
Ex: Find the molar mass for MgCl2
Molar mass = massMg + 2 (massCl)
= g + 2( g)
= g g
= g MgCl2

26. Calculate # moles of compound from given mass of compound

27. Calculate mass of compound from given # moles of compound

28. Determine # atoms or ions in a mass of a compound

29. Empirical & Molecular Formulas
Section 11.4

30. Explain what is meant by the % composition of a compound

31. Determine the empirical & molecular formulas for compound from mass % & actual mass data

32. The formula for a hydrate
Section 11.5

33. What is a hydrate?

34. How does its name reflects its composition?

35. Determine the formula for a hydrate from laboratory data