1. Factor Label Method and the Mole
Chapter 8
Factor Label Method and the Mole

2. What is Avogadro’s Favorite Novel?

3. What is Avogadro’s Favorite Novel?
Molby Dick

4. An equality is a ratio is a conversion factor.
1.61 km = 1 mile
1 pound = kilograms
Density of Aluminum = 2.7 g/cm3
Land speed record = 763 miles/hr

5. What Do We Know About the Mole

6. What Do We Know About the Mole
1 mol = 6.02 x 1023 _________

7. What Do We Know About the Mole
1 mol = 6.02 x 1023 particles
Any equality or ratio can be made into a conversion factor and then used to solve problems with the factor label method.

8. Avogadro’s Number as a Conversion Factor
6.02 x 1023 “particles”
1 mole or
1 mole
Note that particles could be atoms, molecules, formula units, ions, etc.

9. A Mole of Particles Contains 6.02 x 1023 particles
= x 1023 C atoms
= x 1023 H2O molecules
= x 1023 NaCl “molecules”
(technically, ionic compounds are not molecules, they are called formula units)
1 mole C
1 mole H2O
1 mole NaCl

10. 1 mol Na+ = ? 1 mol SO42- = ?
6.02 x 1023 Na+ ions 6.02 x 1023 SO42- ions

11. What Do We Know About the Mole

12. What Do We Know About the Mole
1 mol of any substance = it’s gfm

13. Gram Formula Mass (Molar Mass) of an atom
1 mole of C atoms = g

14. Gram Atomic Mass (Molar Mass) of an atom
1 mole of Mg atoms
6.02 x 1023 Mg atoms
24.3 g

15. Gram Formula Mass (Molar Mass) of an atom
1 mole of Cu atoms
6.02 x 1023 Cu atoms
63.5 g

16. Gram Formula Mass (Molar Mass) of Molecules and Compounds

17. Gram Formula Mass (Molar Mass) of Molecules and Compounds
What is the mass of 1 mol of
calcium phosphate?
Gram Formula Mass of Ca3(PO4)2
3 x = 120.3
2 x =
8 x = 128.0
= g/mol
= 6.02 x 1023 Ca3(PO4)2 formula units

18. List “2” things you know about a mole of H.
1 mole H = 6.02 x 1023 H atoms
1 mole H = 1.0g
What could we use these equalities to do in a factor label problem?

19. List “2” things you know about a mole of H2O
1 mole H2O = 6.02 x 1023 H2O molecules
1 mole H2O = 18.0g

20. List “2” things you know about a mole of Na2O
1 mole Na2O = 6.02 x 1023 Na2O formula units
1 mole Na2O = 62.0g

21. Converting Moles and Grams
Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 8.62 moles of Al? a

22. 1 mole Al = ?

23. 1 mole Al = ?
1 mole Al = 27.0 g Al

24. What are the conversion factors?
1 mole Al = 27.0 g Al

25. What are the conversion factors?
1 mole Al = 27.0 g Al
27.0g Al or mol Al
1 mol Al g Al

26. What are the conversion factors?
1 mole Al = 27.0 g Al
27.0g Al or mol Al
1 mol Al g Al
Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 8.62 moles of Al?

27. Conversion factors for Al
1 mole Al = 27.0 g Al
Conversion factors for Al
27.0g Al or mol Al
1 mol Al g Al
8.62 moles Al

28. Conversion factors for Al
1 mole Al = 27.0 g Al
Conversion factors for Al
27.0g Al or mol Al
1 mol Al g Al
8.62 moles Al g Al
1 mole Al
= 233 g Al

29. How many Al atoms are in the bicycle frame?

30. How many Al atoms are in the bicycle frame?
8.62 moles Al

31. How many Al atoms are in the bicycle frame?
8.62 moles Al
1 mole Al

32. How many Al atoms are in the bicycle frame?
8.62 moles Al
6.02 x 1023 Al atoms
1 mole Al

33. How many Al atoms are in the bicycle frame?
8.62 moles Al
6.02 x 1023 Al atoms
1 mole Al
= 5.19 x 1024 Al atoms

34. How many sodium atoms are in 0.120 mol Na?

35. How many sodium atoms are in 0.120 mol Na?
= 7.22 × 1022 atoms Na
0.120 mol Na ×
1 mol Na
6.02 × 1023 atoms Na

36. How many moles of potassium are in 1.25 × 1021 atoms K?

37. How many moles of potassium are in 1.25 × 1021 atoms K?
= 2.08 × 10-3 mol K
1.25 × 1021 atoms K ×
1 mol K
6.02 × 1023 atoms K

38. What is the mass of 1.33 moles of titanium, Ti?

39. What is the mass of 1.33 moles of titanium, Ti?
= 63.7 g Ti
1.33 mole Ti ×
47.9 g
1 mole Ti

40. How many moles are in 253g of magnesium nitrate?

41. How many moles are in 253g of magnesium nitrate?
Mg(NO3)2

42. How many moles are in 253g of magnesium nitrate?
253g Mg(NO3)2 ×
1 mol Mg(NO3)2
148.3 g Mg(NO3)2
= 1.71 mol Mg(NO3)2

43. What is the mass of 2.55 × 1023 atoms of lead?

44. What is the mass of 2.55 × 1023 atoms of lead?
2.55 × 1023 atoms Pb ×
1 mol Pb
6.02×1023 atoms Pb
207.2 g Pb
1 mole Pb ×
= 87.8 g Pb

45. How many O2 molecules are present in 0.470 g of oxygen gas?

46. How many O2 molecules are present in 0.470 g of oxygen gas?
1 mol O2
32.0 g O2
6.02×1023 molecules O2
1 mole O2 ×
8.84 × 1021 molecules O2