1. All Roads Lead to the Mole
CHEMICAL QUANTITIES
All Roads Lead to the Mole

2. Chemical Quantities Dozen: Baker as Mole: Chemist Measuring donuts:
1 dozen = 12 donuts (count)
1 dozen = 500 g donuts (mass)
1 dozen = 1 box donuts (volume)
Measuring steam (H2O gas):
1 mole = 6.02 x 1023 H2O molecules (count)
1 mole = 18.0 g H2O (mass)
1 mole = 22.4 L H2O (volume) at STP

3. Count Amedeo Avogadro 1776-1856
Lawyer who became interested in math and physics
Discovered that equal volumes of different gases contained an equal number of particles.
9 years after his death, Joseph Loschmidt determined a constant and named it after Avogadro.

4. Not to be confused with the delicious fruit
AVOGADRO’S CONSTANT = 6.02 x 1023
Not to be confused with the delicious fruit

5. AVOGADRO’S CONSTANT = 6.02 x 1023
1 mole = 6.02 x 1023 particles
1 mole = molar mass (grams)
1 mole (of a gas at STP) = 22.4 L

6. The mole is to chemists as
the dozen is to bakers.

7. A Mole Balance

8. Believe it or not, students all over the country celebrate National Mole Day!
National Mole Day Foundation, INC.
Mole Day

9. How BIG
is a MOLE?
5 Pound Bag of Sugar contains 6.6 moles Of C12H22O11
1 Liter bottle of Water contains 55.5 moles H20
6.02 x 1023 Grains of Sand: Would be more than all of the sand on Miami Beach.
6.02 x 1023 Blood Cells: Would be more than the total number of blood cells found in every human on earth.
6.02 x 1023 Watermelon Seeds: Would be found inside a melon slightly larger than the moon.
6.02 x 1023 Pennies: Would make at least 7 stacks that would reach the moon.
6.02 x 1023 Donut Holes: Would cover the earth and be 5 miles (8 km) deep.

10. ...AND YOUR UNITS WILL CARRY YOU!
Draw on NOTETAKERS (and pass out flow Mole Map)
CARRY YOUR UNITS...
Volume
Mass
MOLE
R.P.
Formula Units
Ions
Molecules
Atoms
...AND YOUR UNITS WILL CARRY YOU!

11. Types of Representative Particles
Molecules (break down into atoms)
Atoms
Formula Units (break down into ions)
Ions

12. Naming Representative Particles
Pure Substance
Element
Monotomic
Charged
ION
Neutral
ATOM
Polyatomic
MOLECULE
Compound
Molecular
Ionic
FORMULA
UNIT

13. Naming Representative Particles
Examples: Name the representative particle for each substance given. For each molecule, state how many atoms are present. For each formula unit, state how many ions make up the ionic compound.
H+:
Cl2:
C2H6:
Cu(NO3)2:
Al:
NaCl:
ION
MOLECULE – 2 ATOMS per molecule
MOLECULE – 8 ATOMS
FORMULA UNIT – 3 IONS per Form.U.
ATOM
FORMULA UNIT – 2 IONS per Form.U.

14. WS: Representative Particles
Do WS #1-20

15. 1 mole = Avogadro’s Number = 6.02 x 1023 R.P.’s
Mole R.P. Calculations
1 mole = Avogadro’s Number = 6.02 x 1023 R.P.’s
R.P.
MOLE

16. R.P. Example 1: How many moles are in 1.4 x 1022 molecules of H2O?

17. R.P. Example 2: How many representative particles are in 2.6 mol CO2?

18. R.P. Example 3: How many atoms are in 5.2 mol CO2?

19. DO WS:
The Mole and Avogadro’s Number

20. MOLAR MASS
The molar mass is the mass, in grams, of one mole (6.02  1023 particles) of an element (ion), a covalent molecule or a formula unit.
molar mass (MM) gram atomic mass (gam) molecular weight (MW) gram molecular mass (gmm)
formula mass (FM) gram formula mass (gfm)
formual weight (FW)

21. MASS of one MOLE
Gram atomic mass (gam): the atomic mass (the mass in one mole of a substance) of an element expressed in grams.
Gram molecular mass (gmm): the atomic mass of one mole of a molecular compound.
Gram formula mass (gfm): the sum of the atomic masses of the atoms that are in the formula of a compound.

22. gam, gfm, gmm examples:
Problem: Give the gram atomic mass of hydrogen.
Solution: H = 1H = 1(1.01) = 1.01 g/mol
Problem: Give the gram molecular mass of hydrogen.
Solution: H2 = 2H = 2(1.01) = 2.02 g/mol
Problem: Find the gram formula mass for H2SO4.
Solution: H2SO4 = 2H + 1S + 4O
= 2(1.01) (16.00) = g/mol

23. Molar Mass … a.k.a. Molecular Weight (MW)
molar mass = mass of 1 mole of substance
Molar mass can be determined by adding up the atomic masses from the periodic table (atomic mass goes to 2 decimal places).

24. MW Example 1: = 1C + 4H = 12.01 + 4(1.01) = 16.05 g CH4/mol CH4
Find the MW of CH4.
= 1C + 4H
= (1.01)
= g CH4/mol CH4

25. MW Example 2: =Mg + 2O + 2H =24.31 + 2(16.00) + 2(1.01)
Find the MW of Mg(OH)2.
=Mg + 2O + 2H
= (16.00) + 2(1.01)
=58.33 g Mg(OH)2 /mol Mg(OH)2

26. MW Example 3: Find the MW of MgSO4∙7H2O. =Mg + S + 4O + 7(H2O)
= (16.00) + 7( )
= g MgSO4∙7H2O /mol MgSO4∙7H2O

27. Calculations:
Use Mole Map to help calculate

28. Mole Mass Calculations
1 mole = molar mass (MW) in grams
Mass
MOLE

29. Mass Example 1:
How many grams are in 7.20 moles of dinitrogen trioxide?
dinitrogen trioxide = N2O3
MW of N2O3 = 2N + 3O = 2(14.01) + 3(16.00) = g/mol
1 mole = g N2O3

30. MW of Fe2O3 = 2Fe + 3O = 2(55.85) + 3(16.00) = 159.70 g/mol
Mass Example 2:
Find the number of moles in 92.2 g of iron(III) oxide.
iron(III) oxide = Fe2O3
MW of Fe2O3 = 2Fe + 3O = 2(55.85) + 3(16.00) = g/mol
1 mole = g Fe2O3

31. Make sure you write out all work and include all units!!
Practice Worksheet
Do #1-10 on Mole and Mass WS
Make sure you write out all work and include all units!!

32. Mole Volume Calculations
1 mole = 22.4 L of gas at STP
STP = standard temperature and pressure (0 °C & 1 atm)
Volume
MOLE

33. Volume Example 1:
Determine the volume, in liters, of mol of SO2 gas at STP.

34. Volume Example 2:
Determine the number of moles in 33.6 L of He gas at STP.

35. Density density = mass / Volume
When given the density of an unknown gas, one can multiply by the molar volume to find the MW.
The MW can allow for identification of the gas from a list of possibilities.

36. Density Example (part A):
The density of an unknown gas is g/L at STP. (a) What is the molar mass?

37. Density Example (part B):
The density of an unknown gas is g/L (b) Identify the gas as either nitrogen, fluorine, nitrogen dioxide, carbon dioxide, or ammonia.
MW = g/mol (from part a)
Nitrogen = N2 = 2(14.01) = g/mol
Fluorine = F2 = 2(19.00) = g/mol
Nitrogen dioxide = NO2 = (16.00) = g/mol
Carbon dioxide = CO2 = (16.00) = g/mol
Ammonia = NH3 = (1.01) = g/mol

38. Mixed Mole Conversions
1 mole = x 1023 RP’s = MW = L of
All Roads Lead to the Mole.
Always convert to units of moles first when converting between grams, liters, and representative particles.

39. Mixed Mole Example 2: How many atoms are in 22.0 g of water?
22.0 g H2O × 1 mole H2O g H2O × 6.02×1023 molec. H2O 1 mole H2O × 3 atoms 1 molec. H2O

40. Mixed Mole Example 1:
How many carbon atoms are in a 50.0-carat diamond that is pure carbon? Fifty carats is the same as 10.0 g.

41. Extra questions to review concepts

42. What is the mass of one mole of table salt (NaCl)?
23.0 g
35.5 g
58.44 g
100.0 g
atomic mass Na = g/mol
atomic mass Cl = g/mol
mass of one mole of NaCl = = g

43. What is the mass of 3.7 moles of NaCl?
15.8 g
58.5 g
220 g
6.02 x 1023 g

44. What is the mass of one mole of water (H2O)?
3.0 g
16.0 g
17.0 g
18.02 g
atomic mass H = 1.01 g/mol
atomic mass O = g/mol
mass of one mole of H2O = 2(1.01) = g

45. How many moles are in 152 g of water?
6.02 x 1023 mol