1. WHAT IS A MOLE?

2. Moles: Measuring Matter
A UNIT OF MEASURE!!!
1 mole = 6.02 x 1023 representative particles
atoms, molecules, formula units, ions
Also called Avogadro's number

3. Moles Molar mass of compounds – add up parts
1 mole = 6.02 x 1023 particles
1 mole is also equal to the molar mass of a substance
molar mass = atomic mass with the units g/mol
*g/mol is the same as atomic mass except atomic mass has the units of amu
Molar mass of compounds – add up parts
Find the molar mass of K2CrO4

4. Molar Mass

5. CHALK LAB!!

6. MAKE FLIP CHART: 4 SHEETS

7. Mole Conversions particles to moles # particles 1 mole
6.02 x 1023 particles
moles to particles
# moles x 1023 particles
1 mole
moles to mass (g)
moles molar mass =

8. Mole Conversions Mass (g) to moles mass 1 mol = molar mass
Mass (g) to particles
mass mol x 1023 particles
molar mass mol
particles to mass (g)
particles mol molar mass
6.02 x 1023 particles mol

9. MOLES to Particles Converting moles to particles Conversion Factors
# moles x x 1023 particles
1 mol
Convert 3.5 moles sucrose to molecules

11. Moles continued Converting particles to moles # particles x 1 mole =
6.02 x 1023 particles
Calculate the # moles in 4.50 x 1024 atoms Zn

12. Homework: 2/7
Do problems 1, 6, 7, 16, 17, & 20

13. Moles: Mass and the Mole
Moles to mass:
# moles x # grams
1 mol
How many grams are in 3.00 mol Mn?

14. Moles: Mass and the Mole
mass to moles:
mass x 1 mol
#grams
How many moles are in 525 g Ca?

15. Homework: 2/8
Do problems 8, 9, 12, 13 & 18

16. Moles -2: Mass and the Mole
atoms to mass:
# particles x mol x # grams
6.02 x 1023 particles mol
How much mass is in 5.50 x 1022 atoms of helium?

17. mass to atoms:
mass x 1 mol x x 1023atoms
#grams 1 mol
How many atoms of gold in 25.0 g?

18. QUIZ Tomorrow over mole conversions!!
Homework 2/9
Do problems: 10, 11, 14 & 15
QUIZ Tomorrow over mole conversions!!

19. Moles -4: Empirical and Molecular Formulas
percent composition
mass of element x 100 = % by mass
mass of compound
percent always adds up to 100
Find % of H and O in water

20. Moles -4 continued
Empirical formula – smallest whole # mole ratio of the elements
* May or may not be actual molecular formula
To get:
Change g to mol
Get mole ratio
The ratios are the subscripts
*If you are given % composition: assume % is grams
Find the empirical formula of a sample with g S and g O.

21. Moles -4 continued
Molecular formula – specific # of atoms of each element in compound
experimentally determined molar mass = n
mass of empirical formula
multiply n by empirical formula subscripts
molecular formula = (empirical formula)n
Problem: The empirical formula of a substance is CH. The molecular mass of the compound is 78 amu. What is the molecular formula of the compound?

22. EMPIRICAL & MOLECULAR FORMULA PRACTICE
Chemical analysis indicates a sample is composed of 40.68% C, 5.08% H and 54.24% O and has a molar mass of g/mol. Determine the empirical and molecular formulas of succinic acid

24. Moles: Moles of Compounds
YOU can find moles of a part of a compound
How many moles of F are in 5.50 moles CCl2F2?
* Get ratio from formula.
Determine the number of moles of Al ions in 1.25 mol Al2O3

25. Moles -5: The formula for a Hydrate
Hydrate – compound with a specific # of water molecules bound to its atoms
Methane Hydrate

26. Naming Hydrates Naming: name salt • prefix hydrate CaCl2•2H2O
calcium chloride dihydrate
Prefixes are the same as those used for covalent compounds
Anhydrous – without water used to store water or as drying agents
Used to store solar energy i.e. sodium sulfate decahydrate

27. Hydrate Practice
Write the chemical formula of lithium nitrate trihydrate.
Write the chemical formula for sodium sulfate decahydrate.
What is the molar mass of the hydrate lithium nitrate trihydrate?
What is the percent of water in sodium sulfate decahydrate?