11

All Roads Lead All Roads Lead to Mole Cityto Mole City

22

What Have We Learned What Have We Learned Thus Far (10.1)Thus Far (10.1)

How to convert from molecules to moles/moles

to molecules

33

Molecules to Mole ….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= 0.122 mole BaSO46.02 x 1023

molecules BaSO4

Molecules / Avogadro’s # = Moles

44

Moles to Molecules….Moles to Molecules….

If you have 0.632 moles of barium sulfate, how many molecules of BaSO4 do you have?

0.632 moles BaSO4

1 mole BaSO4

= 3.80 x 1023 molecules BaSO4

6.02 x 1023 molecules BaSO4

Moles x Avogadro’s # = Molecules

55

What Have We Learned What Have We Learned Thus Far (10.1)Thus Far (10.1)

How to calculate the molar mass of a

compound

66

For instance ….For instance ….

What is the molar mass of CuHAsO3?

Cu = 1(63.5) = 63.5 g/molH = 1(1.0) = 1.0 g/molAs = 1(74.9) = 74.9 g/molO = 3(16.0) = 48.0 g/mol

= 187.4 g/mol

77

What Have We Learned What Have We Learned Thus Far (10.2)Thus Far (10.2)

How to convert from grams to moles/moles

to grams

88

Grams to Moles ….Grams to Moles ….

If you have 12.212 g of CuHAsO3. How many moles do you have?

12.212 g CuHAsO3

187.4 g CuHAsO3

Cu = 1(63.5) = 63.5H = 1(1.0) = 1.0As = 1(74.9) = 74.9O = 3(16.0) = 48.0

= 187.4 g/mol

1 mole CuHAsO3 = .065165421 mole CuHAsO3

= .06517 mole CuHAsO3

= 6.517 x 10-2 mole CuHAsO3

Grams / Molar Mass = Moles

99

Moles to 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

Cu = 1(63.5) = 63.5H = 1(1.0) = 1.0As = 1(74.9) = 74.9O = 3(16.0) = 48.0

= 187.4 g/mol

1 mole CuHAsO3

= 288.596 g CuHAsO3

= 289 g CuHAsO3

(only 3 sig figs)

Moles x Molar Mass = Grams

1010

Delayed Objective (10.2)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

1111All Roads Go Through Mole CityAll Roads Go Through Mole City

Gramville

Mole CityMultiply by molar mass

Gas Station

Divide bymolar mass

Multiply by6.02 x 10 23

Divide by

22.4 L

Divide by6.02 x 10 23

Multip

ly by

22.4 L

MoleculeTown

1212Sample mixed mole problem: Sample mixed mole problem: Molecules to GramsMolecules to Grams

If you have 3.45 x 1025 molecules of NH3, how many grams do you have?

3.45 x 1025 molecules NH3

17.0 g NH3

N = 1(14.0) = 14.0 g/molH = 3(1.0) = 3.0 g/mol

molar mass NH3 = 17.0 g/mol

1 mol NH3

= 974.252 g NH3

= 974 g NH3

6.02 x 1023 molecules NH3

1 mol NH3

1313Sample mixed mole problem: Sample mixed mole problem: Grams to Molecules/AtomsGrams to Molecules/Atoms

If you have 66.23 g of CO2, how many oxygen atoms do you have?

66.23 g CO2

C = 1(12.0) = 12.0 g/molO = 2(16.0) = 32.0 g/mol

molar mass CO2 = 44.0 g/mol

1 mol CO2

= 1.8123 x 1024 oxygen atoms

= 1.81 x 1024 oxygen atoms

6.02 x 1023 molecules CO21 mol CO2

44.0 g CO2 1 molecule CO2

2 atoms oxygen