1. Unit V: The Mole Concept
V.3. Multiple Conversions between Moles, Mass, Volume and Number of Particles

2. THE MIGHTY MOLE DIAGRAM

3. THE MIGHTY MOLE DIAGRAM
grams
moles
molecules
atoms L
@STP

4. Mighty Mole Questions Grams to Molecules conversion
How many molecules are in a 2.62 g sample N2O4
Plan: g  mol  molecules
1.71 x 1022 molecules

5. Mighty Mole Questions Molecules to Litres Conversion
Find the volume occupied by x 1026 molecules of SO2 at STP?
Plan: molecules  moles  L
4480 L

6. Mighty Mole Questions Grams to Atoms Conversion
Find the total number of atoms in a g glass of water.
Plan: g  mol  molecules  atoms date leaves
3.01 x 1025 atoms

7. Mighty Mole Questions Grams to Molecules
g CH4 = ? Molecules
Plan: grams  moles  molecules
1.29 x 1021 molecules

8. Mighty Mole Questions Litres to Molecules Conversion
54.3 L of NO2 = ? Molecules
1.46 x 1024 molecules

9. Mighty Mole Questions Molecules to Grams Conversion
Find the mass of 3.68 x 1025 molecules of NO2 (g)?
2.81 x 108 grams

10. Mighty Mole Questions Molecules  Litres (STP) Conversion
1.35 x 1026 molecules of NH3 = ? L at STP
5.03 x 103 L

11. Mighty Mole Questions Grams to Atoms Conversion
Find the number of atoms in a g sample of C3H8?
4.30 x 1025 atoms

12. Mighty Mole Questions
Find the number of “O” atoms in a 60.0L sample of N2O4
6.45 x 1024 “O” atoms

13. Hebden Do Exercises 22 (a); 23 (a-d); 24 on pages 86-87 of Hebden
Do Exercises 36 (a); 37 (a) ; 38 (c); 42 (b, h, m) on pages of Hebden
Assignment #9

14. DENSITY AND MOLES
Density is the mass per unit of volume M
D V

15. THE MIGHTY MOLE DIAGRAM
grams
moles
molecules
atoms L
@STP

16. FOR GASES ONLY Density of Gases at STP Density STP = DSTP
Mass of 1 mole
Volume 1 mole
= Molar Mass
22.4
= MM (g/mol)
22.4 (L/mol)
FOR GASES ONLY

17. Density of Gases at STP Find the density of P2O5 gas at STP? DSTP
6.34g/L
= MM (g/mol)
22.4 (L/mol)

18. Density of Gases at STP Calculate the density of O2 (g) at STP? DSTP
1.43 g/L
= MM (g/mol)
22.4 (L/mol)

19. Density of Gases at STP
The density of air is about 1.29 g/L. What is the density of Cl2 (g) at STP?
DSTP
3.17 g/L  so Cl2 (g) is more dense than air
= MM (g/mol)
22.4 (L/mol)

20. Molar Mass From Density at STP
DSTP
= MM (g/mol)
22.4 (L/mol)
MM = DSTP x 22.4

21. Molar Mass From Density at STP
An oxide of chlorine has a density of g/L at STP
Find the molar mass of this gas
Determine the molecular formula for this gas
MM = DSTP x 22.4

22. Molar Mass From Density at STP
An oxide of chlorine has a density of g/L at STP
6.75 g/mol
MM = DSTP x 22.4

23. Molar Mass From Density at STP
ClO 
ClO2
ClO3

24. Molar Mass From Density at STP
A mystery gas has a density of g/L at STP. It is an element.
Find it’s molar mass
38.0 g/mol
MM = DSTP x 22.4

25. Molar Mass From Density at STP
Given the molar mass of 38.0 g/mol
Guess the gas

26. Density of Solids and Liquids
WHAT TO DO WHEN YOU DON’T HAVE A GAS!!
M = D x V M
D V

27. THE MEGA MIGHTY MOLE DIAGRAM
D V
D x V
grams
moles
molecules
atoms L
@STP

28. Example: Density  Molecules Conversion
The density of Boron (solid) is 2.34 g/mL. How many molecules are there in a 60.0 mL chunk of boron?
Plan: D x V  g  mol  molecules
7.83 x 1024 molecules of Boron

29. Example Atoms  Volume Conversion
Liquid mercury has a density of g/mL. Find the volume occupied by x 1027 atoms. (Hg is monatomic)
Plan: atoms  molecules mol g volume
44413 mL or 44.4L

30. Example Moles  Density Conversion
A 5.00 mL sample of solid lead is known to contain moles of Pb. Calculate the density of Pb.
Plan: mol g density
11.35 g/mL

31. Example: Density  MM (STP)
250.0 mL of a gas which is known to be a fluoride of sulphur has a mass of 1.63 g at STP
a) Find the molar mass
146.0g/mol

32. Example Density  MM (STP)
(b) What is the molecular formula for the gas. (Calculated Molar Mass = 146.0g/mol – fluoride of sulphur)
SF6 = g/mol

33. Example D  MM (STP)
1.25 L of disilane gas has a mass of 3.47 g. What is the molar mass? (Assume STP)
Plan: Density  MM
62.2 g/mol

34. Example Density  MM (STP)
It is found that a mole sample of gas occupies a volume of mL. Calculate the molar volume in L/mol.
18.33 L/ mol

35. Hebden Do Exercises 25, 27, 28 and 29 on pages 88 of Hebden
Do Exercises 40 (e), 41 (a, f, h, k), 42 (b, e, n) on pages 89 of Hebden
Do Hand-In Density Worksheet

36. Mid-Unit Test
Mega Mighty Mole Diagram
Mole Conversions