1. All Roads Lead to Mole City

2. What Have We Learned Thus Far (10.1)
How to convert from molecules to moles/moles to molecules

3. Molecules / Avogadro’s # = Moles
Molecules to Mole ….
If you have 7.36 x 1022 molecules of barium sulfate, how many moles of BaSO4 do you have?
7.36 x 1022
molecules BaSO4
1 mole BaSO4
= mole
BaSO4
6.02 x 1023
molecules BaSO4
Molecules / Avogadro’s # = Moles

4. Moles x Avogadro’s # = Molecules
Moles to Molecules….
If you have moles of barium sulfate, how many molecules of BaSO4 do you have?
0.632
moles BaSO4
6.02 x 1023
molecules BaSO4
= 3.80 x 1023
molecules BaSO4
1 mole BaSO4
Moles x Avogadro’s # = Molecules

5. What Have We Learned Thus Far (10.1)
How to calculate the molar mass of a compound

6. For instance …. Cu = 1(63.5) = 63.5 g/mol H = 1(1.0) = 1.0 g/mol
What is the molar mass of CuHAsO3?
Cu = 1(63.5) = g/mol
H = 1(1.0) = g/mol
As = 1(74.9) = g/mol
O = 3(16.0) = g/mol
= g/mol

7. What Have We Learned Thus Far (10.2)
How to convert from grams to moles/moles to grams

8. Grams / Molar Mass = Moles
Grams to Moles ….
If you have g of CuHAsO3. How many moles do you have?
g CuHAsO3
1 mole CuHAsO3 =
mole CuHAsO3
187.4 g CuHAsO3
Cu = 1(63.5) =
H = 1(1.0) =
As = 1(74.9) =
O = 3(16.0) =
= mole CuHAsO3
= x 10-2 mole CuHAsO3
= g/mol
Grams / Molar Mass = Moles

9. Moles x Molar Mass = Grams
Moles to Grams ….
If you have 1.54 moles of CuHAsO3. How many grams do you have?
1.54 mol CuHAsO3
187.4 g CuHAsO3
= g CuHAsO3
1 mole CuHAsO3
Cu = 1(63.5) =
H = 1(1.0) =
As = 1(74.9) =
O = 3(16.0) =
= 289 g CuHAsO3
(only 3 sig figs)
= g/mol
Moles x Molar Mass = Grams

10. Learn how to convert between moles and volume (L, gas)
Delayed Objective (10.2)
Learn how to convert between moles and volume (L, gas)
We will learn this when we derive the Ideal Gas Law in Chapter 14.3, but …… just multiply or divide by 22.4 L

11. All Roads Go Through Mole City
Divide by
6.02 x 1023
Molecule
Town
Multiply by
6.02 x 1023
Divide by
molar mass
Multiply by molar mass
Divide by
22.4 L
Mole City
Gramville
Multiply by 22.4 L
Gas Station

12. Sample mixed mole problem: Molecules to Grams
If you have 3.45 x 1025 molecules of NH3, how many grams do you have?
3.45 x 1025
molecules NH3
1 mol NH3
17.0 g NH3
= g NH3
6.02 x 1023
molecules NH3
1 mol NH3
= 974 g NH3
N = 1(14.0) = g/mol
H = 3(1.0) = g/mol
molar mass NH3 = 17.0 g/mol

13. Sample mixed mole problem: Grams to Molecules/Atoms
If you have g of CO2, how many oxygen atoms do you have?
6.02 x 1023
molecules CO2
66.23 g CO2
1 mol CO2
2 atoms oxygen
44.0 g CO2
1 mol CO2
1 molecule CO2
= x 1024 oxygen atoms
= x 1024 oxygen atoms
C = 1(12.0) = g/mol
O = 2(16.0) = g/mol
molar mass CO2 = 44.0 g/mol