Warm Up
11-18-15
1. Which atom did Avogadro based his
experiment on?
2. How many molecules are in 1 mol of
oxygen gas?
3. The molar mass of 1 CO2 compound is ___
4. What is the mass of 3 CO2 compounds?
5. Define sophmole.
Agenda
Homework
Notes Unit 5-5
Group solving problems
Online HW
Nov 20 - Quiz Unit 5
Nov 21 - Online HW Unit 5
Dec 9 - Deadline to retake
quizzes and turn in absent work
Notes Unit 5-5
Moles Conversion
Bubble Diagram
• Using moles to convert between mass and
the amount of atoms in a compound
Conversion Types
•
•
•
•
•
•
Moles to grams
Moles to atoms/molecules
Grams to moles
Atoms/molecules to moles
*Grams to atoms
*Atoms to grams
Mole to Gram Conversions
1) What is the mass of 2.5 moles of
phosphorus?
Mole to Gram Conversions
• Multiple the # of moles
given by the molar mass moles A  grams A
Molar mass
• Example: What is the
(from periodic
mass of 2.5 moles of
table)
phosphorus?
• Molar mass=30.97 g/mol
2.5 mol P
30.97 g P
1 mol P
=
2.5 x 30.97 g P
1
=
77 g P
Gram to Mole Conversions
2) How many moles are in 12 grams of
FeO?
Gram to Mole Conversions
• Multiply the # of grams grams A  moles A
Molar mass
given by the inverse of
(from periodic
the molar mass.
table)
• Example: How many
moles of iron are in 12
grams of iron?
12 g Fe 1 mol FeO
71.85 g Fe
=
12 mol Fe
71.85
=
0.169
moles Fe
Mole to Atoms
3) How many atoms are in 3.00 moles of
Na?
Mole to Atoms
• Multiple the # of
moles given by
Avogadro’s number
• Example: How
many atoms are in
3.00 moles of Na?
3.00 mol Na
6.02 x 1023
atoms Na
1 mol Na
moles A  atoms A
Avogadro’s Number
(6.02 x 1023 particles/mol)
=
3.00 x (6.02 x 1023)
atoms Na
1
=
1.81 x 1024
atoms Na
Atoms to Moles
4) If you have 7.45 x 1025 molecules of O2
gas, how many moles do you have?
Atoms to Moles
• Multiple the # of moles
given by the inverse of
Avogadro’s number
• Example: If you have
7.45 x 1024 molecules
of Cu, how many moles
do you have?
7.45 x 1025
molecules Cu 1 mol Cu
6.02 x 1023
molecules Cu
=
atoms A  moles A
Avogadro’s Number
(6.02 x 1023
particles/mol)
7.45 x 1025 mol Cu
6.02 x 1023
=
124 mol
Cu
Grams to Atoms
5) How many atoms are in 26 grams of
cobalt?
Grams to Moles to Atoms
Grams A  moles A  molecules A
Molar mass
(from periodic
table)
Avogadro’s Number
(6.02 x 1023
particles/mol)
• 2 steps! 1st multiply by the inverse of the molar
mass, 2nd multiply by Avogadro’s number
• Example: How many atoms are in 26 grams of
cobalt?
26 g Co 1 mol Co
58.93 g Co
6.02 x 1023 molecules Co
1 mol Co
=
2.7 x 1023
molecules Co
Atoms to Grams
6) What is the mass of 8.60 x 1023 atoms of
NaCl?
Atoms to Moles to Grams
molecules A  moles A  Grams A
Avogadro’s Number
(6.02 x 1023
particles/mol)
Molar mass
(from periodic
table)
• 2 steps! 1st multiply by the molar mass, 2nd
multiply by the inverse of Avogadro’s number
• Example: What is the mass of 8.60 x 1023
molecules of As?
8.60 x 1023
molecules As
1 mol As
1023
6.02 x
molecules As
74.92 g As
1 mol As
= 107 g As
Group work
• Work on questions #1-9 with a partner
ANSWERS:
1) 1 x 103
2) 7.16 x 10-3
3) 1.67 x 10-4
4) 4.454 x 1024
5) 2.53 x 1021
6) 3.01 x 1024
7) 96 grams
8) 5.778 x 10-2
9) 722.16 grams
Assignments
• Summary
• Online HW
https://quest.cns.utexas.edu/