Moles are a Chemist Best Friend
Chapter 10
nclark.net
Moles are a Chemist Best Friend
Chapter 10
nclark.net
Objectives: Moles are a Chemist Best Friend
• I can identify what a mole is in chemistry.
• I can convert between representative particles of
matter and moles.
• I can convert between the mass of matter and
moles.
• I can convert between the volume of matter and
moles.
Mole Bell Ringer
1. What are three ways we measure matter?
2. What is a mole in chemistry?
3. What are examples of representative
particles in chemistry?
4. What is the conversion between
representative particles and moles?
Measuring Matter
What are three ways we can measure matter?
1. mass
2.quantity
3. volume
hermitwoods.com
Measuring Apples
www.123rf.com
stockphotos.it
flickr.com
Grouping Matter
• Easy way to measure all matter.
r1
Gross of pencils=155
Dozen dougnuts=12
Ream of paper =500
Byte of stored information=4
Grouping Representative Particles
• How would we group representative particles of
matter?
Representative particles: substances that make-up
matter.
nclark.net
Classification of Matter
Grouping Representative Paraticles
• How would we group representative particles that
make-up matter?
Representative particles: substances that make-up
matter.
(atoms, molecules or
ionic compounds)
nclark.net
Grouping Representative Particles
A mole is a unit of measurement that is used to
group representative particles.
1 mole = 6.02x1023 representative particles
(Avogadro’s Number)
•“The Mole is a Unit”
(nclark.net)
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Converting Moles to Representative Particles
Ex. Propane (C3H8) is a gas used for cooking and
heating. How many molecules of propane is equal
to 2.4 moles of propane?
Conversion: Representative Particles to Moles
Ex. Magnesium is a light metal used in the
manufacture of aircraft and automobile wheels.
How many moles of magnesium equals 1.25x1023
atoms of magnesium?
Measuring Matter
What are three ways we can measure matter?
1.
2.
3.
hermitwoods.com
Grouping Matter
• Easy way to measure all matter.
r
Gross of pencils=
Dozen dougnuts=
Ream of paper =
Byte of stored information=
Mole Map
mass
molar mass
1mol
1mol
molar mass
moles
22.4L
1mol
1mol
6 .02 x 10 23 part icles
1mol
22.4L
6 .02 x 10 23 part icles
1mol
volume
at STP
number of
represent at ive
part icles
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Pre-AP Chemistry(3/28)
Objectives:
• Convert between moles and representative
particles of a substance.
• Convert between moles and mass of a
substance.
Homework:
Law of Conservation of Mass-Final Draft Typed
Mole Problems
Have a fun and safe spring break. 
Bell Ringer: Moles
1. Define and give two examples of a representative
particle.
2. a. What is a mole?
b. How many atoms are in a mole of Cu?
3. How many moles are in 4.65x1024 molecules of CO2 ?
Conversions: Mole-Representative Particles
(Homework Problems Key)
1.
2.
3.
4.
5.
1.
2.
3.
4.
5.
1.2x1024 molecules
9.0x1023 molecules
4.5x1023 molecules
9.0x1024 molecules
2.1x1023 molecules
1.00 moles
2.00 moles
2.5x10-4 moles
5.6x102 moles
1.2x10-4 moles
(2sig. Figs)
(2 sig figs)
(2 sig figs)
(2 sig figs)
(2 sig figs)
(3 sig figs)
(3 sig figs)
(2 sig figs)
(2 sig figs)
(2 sig figs)
Conversion: Mole-Representative Particles
Homework Problems
Converting Moles to Mass
• How do we convert from moles to mass of a
substance?
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Converting Moles to Mass
• How do we convert from moles to mass?
Mole Conversions: 4.24
Objectives:
• I can identify what a mole is in chemistry.
• I can convert between representative particles of
matter and moles.
• I can convert between the mass of matter and
moles.
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Conversion: Moles- Mass
• Mole-Mass Conversion:
1 mole of a substance = molar mass of the substance
• Molar mass = substance’s atomic mass in grams
Examples:
• A mole of sodium has a molar mass of?
• A mole of H2O has a molar mass of?
Molar Mass of an Element
• Molar mass = element’s atomic mass(grams)
• Round atomic mass to tenths place.
Ex. A mole of sulfur has a molar mass of?
Ex. A mole of sodium has a molar mass of?
Molar Mass of a Compound
• Molar mass = sum of the elements’ atomic masses
in the compound
• Need chemical formula to calculate the molar
mass of a compound.
Ex. A mole of NaCl has a molar mass of?
Ex. A mole of H2O has a molar mass of?
Mole Conversions: 4.25
Objectives:
• I can identify what a mole is in chemistry.
• I can convert between representative particles of
matter and moles.
• I can convert between the mass of matter and
moles.
Bell Ringer: Chemistry
1. Classify each substance below with the correct
representative particle. (atom, ionic compound, or
molecule)
a. Na2O
b. Fe c. H2
d. Ne
2. How many atoms of Cu are in 2.5 moles of
copper?
3. What is the molar mass of Al2(CO3)3?
4. How many grams of Al2(CO3)3 are in 3.25 moles of
Al2(CO3)3?
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Bell Ringer: Chemistry
1. Classify each substance below with the correct
representative particle. (atom, ionic compound, or
molecule)
a. Na2O
b. Fe c. H2
d. Ne
2. How many atoms of Cu are in 2.5 moles of
copper?
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Bell Ringer: Chemistry
3. What is the molar mass of Al2(CO3)3?
4. How many grams of Al2(CO3)3 are in 3.25 moles of
Al2(CO3)3?
Mole Conversions: 2-Step Conversions
http://mysite.cherokee.k12.ga.us
Mole Conversions:
Mole Conversion Map
http://mysite.cherokee.k12.ga.us
Mole Conversions: 4.28
Objectives:
• I can identify what a mole is in chemistry.
• I can convert between representative particles and
mass by using the mole.
Homework:
• Mole conversion quiz tomorrow.
• Mole Conversions: 2-step problems (last page)
Fun with Moles Review
• Review mole conversions
http://mysite.cherokee.k12.ga.us
Mole Conversions: 4.29
Infinite Campus Update:
• Fun With Moles Wksht-Due asap (14pts.)
• Chemical Reactions Test updated (30pts.)
Objectives:
• I can convert between representative particles and
mass by using the mole.
• Mole Quiz
• I can calculate % composition of compound
Homework:
• % Composition Worksheet
Mole Conversions: 2-Step Conversions
http://mysite.cherokee.k12.ga.us
Mole Conversions: 4.30
Infinite Campus Update:
•Mole Quiz
Objectives:
•Review Mole Quiz
•I can calculate % composition of compound
Homework:
•% Composition Worksheet
Calculate % Composition of Compound
Ex. What is the % composition of the following
compound, Al(NO2)3 ?
% Composition as a Conversion Factor
• Use % composition data to calculate the mass of
an element from a known sample size.
• Ex. What is the mass of Al in 6.5 g of Al(NO2)3 ?
Percentage Composition of a Compound
What is Percentage Composition of a Compound?
% Composition from Chemical Formula
% mass of element =
Ex. Propane, C3H8 is one of the compounds obtained from
petroleum and is used to fuel homes and gas grills.
Calculate the percent composition of propane.
Mole Conversions: 5.1
Due:
% Composition of Compounds Wksht.
Objectives:
• Address questions over homework.
•I can calculate % composition of sugar in dubble
bubble gum.
•Review Chemical Quantities Study Guide
Homework:
•Work on Chemical Quantities Study Guide
•Mole Conversion Quiz
•Chemical Quantities Exam-Monday
% Composition of Compounds Wksht.
Bubble Gum Lab
• Purpose: Calculate the % composition of
sugar in dubble bubble gum.
Mole Conversions: 5.2
Due:
Bubble Gum Lab (10pts.)
Objectives:
• Mole Conversion Quiz-Retake
• Address results from Bubble Gum Lab
• Review Chemical Quantities Study Guide
Homework:
•Work on Chemical Quantities Study Guide
•Chemical Quantities Exam-Monday
Bubble Gum Lab
• Purpose: Calculate the % composition of sugar
in dubble bubble gum.
• Actual percent sugar in dubble bubble gum:
Chemical Quantities Study Guide
Hydrate Lab
• Hydrated Salt: Cu(SO4)
.H O
• Anhydrous Salt: Cu(SO4)
2
Mole Conversion Lab
-What conversions did we use in this lab?
Mole Conversion Lab
Salt Before:
mass of salt shaker
______
mass of salt shaker + salt______
mass of salt
______
Salt After:
______
______
______
Mole Conversion Lab
Chalk Conversions:
mass of chalk:______
Mole Conversions
• Convert 6.5x1025 cmpds. of MnCl3 to moles of MnCl3
a. What conversion is needed?
a. Write down known(given) and multiply by conversion
fraction.
Mole Conversions
• Convert 1.75 moles of H2SO4 to grams of H2SO4
a. What conversion is needed?
b. Write down known(given) and multiply by conversion
fraction.
Chemical Quantities
• I can recognize that the mole is a standard unit of
measurement for small particles.
• I can convert between the number of particles in
a substance(atoms or compounds) to the number
of moles in a substance.
• I can convert between the mass of a substance
and the number of moles in a substance.
• I can calculate the percent composition of a
compound and use it as a conversion factor.
• I can distinguish the difference between empirical
and molecular formulas.
% Composition from Mass Data
% mass of element =
Ex. When a 13.6 g sample of a compound containing only
magnesium and oxygen is decomposed, 5.4 g of oxygen is
obtained. What is the percent composition each element
in the compound?
% Composition as a Conversion Factor
•What is the mass of Al in 6.5 g of Al(NO2)3 ?
% Composition as a Conversion Factor
•What is the mass of N in 6.5 g of Al(NO2)3 ?
•What is the mass of O in 6.5 g of Al(NO2)3?
Bell Ringer: Chemical Quantities
1. How many grams are in 5.0 moles of Cs3N ?
2.How many moles are in 3.7x1021 cmpds. of NaCl?
3. What is the % composition of Cu2(SO4)?
4. How many grams of Cu are in 9.8 g of Cu2(SO4)?
Empirical vs. Molecular Formulas
Chemical Name
CH
C2H2 (acetylene)
C6H6 (benzene)
CH2O (methanol)
C2H4O2
(ethanoic acid)
C6H12O6 (glucose)
Formula Classification
Cu(SO4)
.
Hydrate Lab
H2O ----> Cu(SO4) + H2O
Use the equation above to help answer the
following questions:
1. What is the hydrate salt in this equation?
2. What is the anhydrous salt in this equation?
3. What is the difference between a hydrated salt
and an anhydrous salt?
4. Is this a physical or chemical reaction?
5. What did you calculate the chemical formula
for the hydrated salt to be?
Copper Sulfate Hydrate