What

1
Whats up with the Mole?
2
How do we measure matter?

• By weight
• We buy bananas by the _______________.
• By volume
• Milk is sold by the ____________________.
• By counting
• There are ________ students in class.

pound
gallon
3
Chemical Quantities

• Many words are used to express a specific
  quantity.
• Pair
• Dozen

2
12
4
How do we measure matter?

• What if I wanted to know how many ATOMS were in
  this copper penny? Would you like to count?
  Could you?

5
Avogadros Number

• You can count particles if you introduce a term
  that represents a specified number of particles.
• In chemistry, the term used to express a specific
  number of particles is a mole.

6
Avogadros Number

• 1 mole 6.02 x 1023 particles
• Thats 602,000,000,000,000,000,000,000
• A very large number!

7
Avogadros Number

• This number is known as Avogadros number, named
  after Amedeo Avogadro (an Italian physicist and
  mathematician).

8
HOW LARGE IS IT???

• 1 mole of hockey pucks would equal the mass of
  the moon!
• 1 mole of pennies would cover the Earth 1/4 mile
  deep!

9
Representative Particles

• Representative particles are units used to
  measure the number of particles in a sample of an
  element or compound.

Substance Representative Particle
element atom
covalent compound molecule
ionic compound formula unit
10
Representative Particles

• What is the representative particle for each of
  these substances?
• copper
• sodium chloride
• water

atom
formula unit
molecule
11
MOLE

• A mole is the SI unit that measures the amount of
  a substance.
• A mole can be related to
• number of particles
• mass
• volume of a gas

12
one mole
Avogadros number of particles
mass in grams using the periodic table
22.4 L of a gas
13
MOLE

• Use dimensional analysis to convert
• moles to molecules
• moles to atoms
• moles to formula units
• moles to grams
• grams to atoms
• and many more.

14
MOLE

• When converting between moles and particles, the
  conversion factor to remember is
• 1 mol 6.02 x 1023 particles
• The particle unit can be atoms, molecules, or
  formula units.

15
Mole/Particle Examples

• 1. How many moles are in 3.25 X 1020 atoms of
  lead?

1 mol 6.02 x 1023 atoms
3.25 x 1020 atoms Pb
1 mol Pb
6.02 x 1023 atoms Pb
5.398671 x 10-4
5.40 x 10-4 mol Pb
16
Mole/Particle Examples

• 2. How many molecules are there in 8.3 moles of
  sugar (C12H22O11)?

1 mol 6.02 x 1023 molecules
8.3 mol C12H22O11
6.02 x 1023 molec. C12H22O11
1 mol C12H22O11
5.0 x 1024 molec. C12H22O11
4.9966 x 1024
17
Mole/Particle Examples

• 3. How many atoms are in 0.425 mol sulfur?

1 mol 6.02 x 1023 atoms
0.425 mol S
6.02 x 1023 atoms S
2.5585 x 1023
1 mol S
2.56 x 1023 atoms of S
18
Mole/Particle Examples

• 4. How many moles are in 5.42 x 1022 formula
  units of NaCl?

1 mol 6.02 x 1023 atoms
5.42 x 1022 Form. U NaCl
1 mol NaCl
6.02 x 1023 Form. U NaCl
0.090033222
0.0900 mol NaCl
19
Molar Mass

• molar mass the mass in grams of one mole of an
  element or compound.

20
Terms that Describe the Mass of a Substance

• Atomic mass mass of one atom of an element
  (unit amu)
• Molecular mass - mass of one molecule of a
  covalent compound (unit amu)
• Formula mass - mass of one formula unit of an
  ionic compound (unit amu)
•  Molar mass - mass of one mole of an element or
  compound (unit g/mol).

21
Molar Mass

• To calculate molar mass
• Obtain all of the masses of the involved elements
  from the periodic table.
• Multiply each elements mass by the subscript.
• Add the resulting products.
• Round the answer to the proper number of decimal
  places.

22
Molar Mass of Element Examples

• Aluminum
• Zinc

26.982
26.98 g/mol
65.38
g/mol
23
Molar Mass of Compounds Examples

• Diphosphorus pentaoxide

P2O5
P
30.974
X 2
61.948

O
15.999
X 5
79.995
141.943
141.94 g/mol
24
Molar Mass of Compounds Examples
3
-1

• Aluminum Hydroxide

Al(OH)3
Al
26.982
X 1
26.982
O
15.999
X 3
47.997

H
1.008
X 3
3.024
78.003
78.00 g/mol
25
Molar Mass of Compounds Examples
2
-3

• Barium phosphate

Ba3(PO4)2
Ba
411.984
137.328
X 3
P
61.948
30.974
X 2

127.992
O
X 8
15.999
601.924
601.92 g/mol
26
Moles to Mass

• Use dimensional analysis to convert
• moles to mass or mass to moles.
• Mass unit grams
• Conversion Factor to Remember
• 1 mol molar mass of the element or compound
• (molar mass g/mol) found on the periodic table

27
Moles to Mass Examples

• How many moles of carbon are in 26 g of carbon?

Carbon 1 mol 12.01 g (from PT)
26 g of C
1 mol of C
2.164862614
12.01 g of C
2.2 mol of C
28
Moles to Mass Examples

• How many grams are there in 2.37 moles of CO2?

C 12.011 x 1 O 15.999 x 2
12.011 31.998

44.009 g 1 mol
44.01 g CO2
2.37 mol CO2
104.3037
1 mol CO2
104 g CO2
29
Moles to Mass Examples

• How many moles are present in 142.1 grams of
  NaCl?

Na 22.990 x 1 Cl 35.453 x 1
22.990 35.453

58.443 g 1 mol
1 mol NaCl
142.1 g NaCl
2.43155373
58.44 g NaCl
2.432 mol NaCl
30
Moles to Mass Examples

• How many grams are in 3.34 moles of potassium
  bromide?

1
-1
KBr
K 39.098 x 1 Br 79.904 x 1
39.098 79.904

119.002 g 1 mol
3.34 mol KBr
119.00 g KBr
397 g KBr
397.46
1 mol KBr
31
Molar Volume of a Gas

• The volume of a gas changes as the temperature
  and pressure change, so the volume is usually
  measured at standard temperature and pressure.
• STP abbreviation for standard temperature and
  pressure
• Standard temperature 0oC 273 K
• Standard pressure 1 atm or 101.3 kPa

32
Molar Volume of a Gas

• At STP, one mole of any gas occupies the same
  volume 22.4 L.

33
Molar Volume of a Gas

• Use dimensional analysis to convert
• volume (liters) to moles
• or moles to volume (liters)
• Conversion Factor to Remember
• 1 mole 22.4 L

34
Molar Volume of a GasExamples

• Determine the volume, in liters, of 0.60 mol SO2
  gas at STP.

35
Molar Volume of a GasExamples

• Assuming STP, how many moles are in 67.2 L SO2?

36
Molar Volume of a GasExamples

• How many moles are in 1.0 x 103 L of C2H6?

37
Molar Volume of a GasExamples

• What is the volume at STP of 3.20 x10-3 mol CO2?

38
Mole Calculations Learned
of Particles (atoms, molecules, formula units)
Liters of gas at STP
1 mol 6.02 x 1023 particles
1 mol 22.4 L
MOLES
1 mol mass from Periodic Table
Mass (grams)