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Agenda 2/10/2015
• 5 A Day Slip Quiz
• Chemical Reactions – test – return for quick review
/not to keep
• The Mole is ? – your thoughts
• Notes
• Homework
5A Day Slip quiz
• Write out the following names and then
write the correct molecular formula or
formula unit for the compound
1. Dihydrogen monoxide
2. Carbon dioxide
3. Copper(II) sulfate
4. Manganese(IV) sulfide
5. Sulfuric acid
A Mole is?
• Your summaries/ thoughts
• What’s Avogadro got to do with it?
Carbon-12
isotope is
stable and
readily
available
all over
the world
The Mole
The Mole is the SI base unit for the
amount of a substance.
The quantity one mole is set by
defining one mole of carbon-12 atoms
to have a mass of exactly 12 grams.
The Mole as a Number of Particles
The mole is the SI unit to measure the
amount of a substance. 12g of carbon12 is set to define one mole and
contains one mole of carbon-12 atoms.
23
10
One mole equals 6.02 x
particles of the substance
(atoms, molecules, ions).
The Mole is a Unit song
http://www.youtube.com/watch?v=1R7NiIum2TI&NR=1
Think about how we assign a name to numbers
all the time:
A dozen eggs/roses/bread rolls
2 dozen
5 dozen
A million
1 000 000
1.0 x 106
Dimensional
analysis p 34
Conversion
factor is a ratio
of equivalent
values used to
express the
same quantity
in different
units (always
equal to 1)
Change units
without
changing
value.
The mole is the SI unit to measure the
amount of a substance. 12g of carbon-12
is set to define one mole and contains
one mole of carbon-12 atoms also
One mole equals 6.02 x 1023
particles of the substance (atoms,
molecules, ions).
1 mole C-12 atoms = 12g C-12
= 6.022 x 1023 atoms
12g C-12
=1
6.022 x 1023atoms
Or
Dimensional
analysis p 34
Conversion
factor is a ratio
of equivalent
values used to
express the
same quantity
in different
units (always
equal to 1)
Change units
without
changing
value.
1 mole C-12 atoms = 12g
= 6.022 x 1023 atoms
6.022 x 1023 = 1
12g C-12
Dimensional
analysis p 34
Conversion
factor is a ratio
of equivalent
values used to
express the
same quantity
in different
units (always
equal to 1)
Change units
without
changing
value.
Qu. How many atoms of carbon-12 are
contained in exactly 12 grams of carbon12?
USING the conversion factor method:
mass x 1 mole
= # of moles
mass of one mole
12 g x 6.02 x 1023 atoms = # of atoms
12 g
12 g x 6.022 x 1023 atoms = 6.022 x 1023
12 g
atoms
Dimensional
analysis p 34
Conversion
factor is a ratio
of equivalent
values used to
express the
same quantity
in different
units (always
equal to 1)
Change units
without
changing
value.
Qu. How many atoms of carbon-12 are
contained in exactly 6 grams of carbon12?
USING the conversion factor method :
mass x 1 mole
= # of moles
mass of one mole
6 g x 6.022 x 1023 atoms = # of atoms
12 g
6 g x 6.022 x 1023 atoms = 3.011 x 1023
12 g
atoms
For mass of one
mole of an
element, look up
atomic mass,
then add grams
as the unit
Qu. How many atoms are in a silicon
sample with a mass of 7g?
USING the same conversion factor
method:
mass x 1 mole
= # of moles
mass of one mole
7 g x 6.02 x 1023 atoms = # of atoms
g
For mass of one
mole of an
element, look up
atomic mass,
then add grams
as the unit
CST Qu. How many atoms are in a silicon
sample with a mass of 7g?
USING the same conversion factor
method:
mass x 1 mole
= # of moles
mass of one mole
7 g x 6.02 x 1023 atoms = # of atoms
28 g
7 g x 6.02 x 1023 atoms = 1.5 x 1023
28 g
atoms
Works
for
molec
ules
too
and
going
other
way!
Qu. How many moles of chlorine gas are
contained in 9.02 x 1023molecules?
USING the conversion factor method:
Molecules have x 1 mole
= # of moles
molecules in 1 mole
9.02x1023 x 1 mole = 1.5 moles
6.02 x 1023
Answer = 1.5 moles
Questions – with equations.
CH4(g) + 2 O2(g)  CO2( ) + 2 H2O(g)
Step 1: Look at the equation (check it is
balanced)
Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
Think
1 mole 2 moles
1 mole 2 moles
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
1 mole 2 moles
Look up
Atomic
masses
OR
Convert
to
number
particles
1 mole 2 moles
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
Look up
Atomic
masses
1 mole 2 moles
1 mole 2 moles
12 + 4
2 x (16+16)
12+16 +16
16g
64 g
44g
2x(1+1+16)
36g
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
1 mole 2 moles
16g
64 g
OR
1 mole 2 moles
44g
36g
6.02x1023 2x(6.02x1023) 6.02x1023 2x(6.02x1023)
Molecules
molecules
molecules
molecules
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
1 mole 2 moles
1 mole 2 moles
6.02x1023 2x(6.02x1023) 6.02x1023 2x(6.02x1023)
6.02x1023
Molecules
12.04x1023
molecules
6.02x1023
molecules
12.04x1023
molecules
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
1 mole 2 moles
6.02x1023
Molecules
OR
12.04x1023
molecules
1 mole 2 moles
6.02x1023
molecules
12.04x1023
molecules
CST Questions – with equations.
Combustion & Exothermic
CH4(g) + 2 O2(g)  CO2(g) + 2 H2O(g)
1 mole 2 moles
6.02x1023
6.02x1023
Molecules
12.04x1023
1.2x1024
molecules
1 mole 2 moles
6.02x1023
6.02x1023
molecules
http://www.nyu.edu/pages/mathmol/textbook/scinot.html
12.04x1023
1.2x1024
molecules
Question: When propane gas is burned in the
presence of oxygen, the following chemical
reaction occurs.
Combustion & Exothermic
C3H8(g) + 5 O2(g) 3CO2(g) + 4 H2O(g)
If 1 mole of propane reacts with 5 moles of
oxygen, then how many molecules of
Carbon dioxide and how many molecules of
water vapor are produced?
C3H8(g) + 5 O2(g) 3CO2(g) + 4 H2O(g)
1 mole
5 moles
3moles 4 moles
? Molecules
? molecules
C3H8(g) + 5 O2(g) 3CO2(g) + 4 H2O(g)
1 mole
5 moles
3moles 4 moles
3x(6.02x1023) 4x(6.02x1023)
C3H8(g) + 5 O2(g) 3CO2(g) + 4 H2O(g)
1 mole
5 moles
3moles 4 moles
3x(6.02x1023) 4x(6.02x1023)
18.06 x 1023
24.08x1023
molecules
molecules
C3H8(g) + 5 O2(g) 3CO2(g) + 4 H2O(g)
1 mole
5 moles
3moles 4 moles
3x(6.02x1023) 4x(6.02x1023)
18.06 x 1023
24.08x1023
molecules
molecules
1.8 x 1024
2.4 x 1024
molecules
molecules
Section 11.1 Measuring Matter
Counting Particles
Practice Problems (p.311 and p. 312)
1, 2, 3, and 4
The Mole is a Unit song
http://www.youtube.com/watch?v=1R7NiIum2TI&NR=1
The mole is the SI unit to measure the
amount of a substance.
One mole equals 6.02 x 1023 particles of
the substance (atoms, molecules, ions)
Where does the number for the unit come
from (and why is it often called Avogadro’s
number)?
Avogadro’s Principle: equal volumes of gases
at the same temperature and pressure
contain equal numbers of particles.
22.4L
22.4L
He
H2
Cl2
28.2 cm
28.2 cm
22.4L
22.4L
Molar Volume: A mole (6.02 x 1023 particles)
of any gas occupies 22.4 L at STP (0°C which
is 273 K and 1 atm).
Homework
Written work due on:
12 Feb, Thursday
• Finish Practice problems set in class p 311 1, 2,
and 3 and Practice Problem 4 on p 312
• The Mole – Chapter 11 Study Guide for
Content Mastery
– Read your textbook and answer questions in the
study guide section 11.1., 11.2 and 11.3.