Moles are a Chemist Best Friend Chapter 10

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Moles are a Chemist Best FriendChapter 10
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Objectives Moles are a Chemist Best Friend

• I can identify what a mole is in chemistry.
• I can convert between moles and representative
  particles of substances.
• I can convert between moles and mass of
  substances.
• I can calculate the percentage composition of
  substances.

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Measuring Matter

• What are three ways we can measure matter?
• 1.
• 2.
• 3.

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Measuring Apples

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Grouping Matter

• Easy way to measure all matter.
• r500

Gross of pencils 144
Dozen dougnuts 12
Ream of paper 500
Byte of information storage 4 bits
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Grouping Matter

• How do scientists group the representative
  particles that make-up matter?
• Representative particles substances that
  make-up matter.
• Examples
• Atoms
• Ionic Compounds
• Molecules (covalent cmpds.)

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Classification of Matter
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Grouping Representative Particles
A mole is used to group representative particles.

• 1 mole 6.02x1023 representative particles
• (Avogadros Number)
• The Mole is a Unit Song (nclark.net)

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Mole Map
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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?

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Convesion 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?

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Mole Map
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Bell Ringer Moles

• Define and give two examples of a representative
  particle.
• a. What is a mole?
• b. How many atoms are in a mole of Cu?
• How many moles are in 4.65x1024 molecules of CO2
  ?

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Conversions Mole-Representative Particles
(Homework Problems Key)

• 1.2x1024 molecules (2sig. Figs)
• 9.0x1023 molecules (2 sig figs)
• 4.5x1023 molecules (2 sig figs)
• 9.0x1024 molecules (2 sig figs)
• 2.1x1023 molecules (2 sig figs)
• 1. 1.00 moles (3 sig figs)
• 2.00 moles (3 sig figs)
• 2.5x10-4 moles (2 sig figs)
• 5.6x102 moles (2 sig figs)
• 1.2x10-4 moles (2 sig figs)

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Conversion Mole-Representative Particles
Homework Problems
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Converting Moles to Mass

• How do we convert from moles to mass?

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Objectives Moles are a Chemist Best Friend

• I can identify what a mole is in chemistry.
• I can convert between moles and representative
  particles of substances.
• I can convert between moles and mass of
  substances.
• I can calculate the percentage composition of
  substances.

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Mole-Mass Conversion
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Mole Map
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Converting Moles to Mass

• How do we convert from the moles of a substance
  to the mass of a substance?

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Conversion Moles- Mass

• Mole-Mass Conversion
• 1 mole of a substance molar mass of the
  substance
• Molar mass substances atomic mass in grams

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Molar Mass of an Element

• Molar mass elements 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?

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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?

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Bell Ringer Chemistry

• What is the representative particle for each
  substance below? (atom, ionic compound, or
  molecule)
• a. Na2O b. Fe c. H2 d. Ne
• How many atoms are in 2.5 moles of copper?
• a. What is the molar mass of silver, Ag?
• b. What is the molar mass of Al2(CO3)3?

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Mole Packet Questions
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Mole-Mass Conversions

• 1 mole molar mass of substance
• Ex. When iron is exposed to air, it corrodes to
  form red-brown rust. How many moles of iron
  (III) oxide are contained in 92.2g of pure Fe2O3?

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Mole Map
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Mole-Mass Conversions

• Ex. What is the mass of 9.45 moles of aluminum
  oxide? (1 mole molar mass of a substance)

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Mole Map
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Mole Conversions

• Mole to Particle Conversion
• 1 mole 6.02x1023 particles (atoms or cmpds)
• Mole to Mass Conversion
• 1 mole molar mass of the substance (grams)

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Mole Map
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Bubble Gum Lab

• Purpose Practice mole conversions and calculate
  the composition of sugar in bubble gum.

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Mole Map
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Chemical Quantities Objectives (Chpt.10)

• I can identify what a mole is in chemistry.
• I can convert between moles and representative
  particles of substances.
• I can convert between moles and mass of
  substances.
• I can calculate the percentage composition of
  substances.

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Bell Ringer Mole Conversions

• Define mole.
• Name the representative particle of each
  substance. (atom, molecule, ionic compound)
• oxygen gas b. sodium sulfide
• potassium d. sulfur dioxide
• What is the molar mass of a substance?
• What is the conversion needed for each problem
  below?
• mole to representative particle conversion?
• mole to mass conversion?

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Chemical Quantities Quiz Questions
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Fun with Moles Review

• Purpose Work together in groups to
  competitively review mole conversion
  calculations learned before spring break.

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Moles Conversion Review Worksheet

1. 0.407 moles
2. 1.8x1024 atoms
3. a. 40.3g b. 74g c. 78g d.96 g
4. 0.0417 mole AgCl
5. 0.35 mole Cu(OH)2
6. 0.258 mol SiO2
7. 51 gH2O2
8. 120 g
9. 1,040 g C5H12
10. 52.7 g Cu

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Mole Map
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Mole Conversions 2 step problems

• How many molecules are there in 100 grams of CCl4
  ?
• 2. How many grams do 1.2x1021 molecules of BCl3
  weigh?

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Mole Conversions 2 step Problems
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Mole Conversion Lab

• Problem How many molecules are present in a
  tablespoon of the following substances?
• sodium chloride
• water
• calcium carbonate
• Design and conduct an experiment that will help
  you solve this problem. Make sure to include a
  hypothesis, data section, and conclusion.

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Mole Conversion Lab Questions
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Mole Map
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Percentage Composition of a Compound

• Percent of mass each element contributes to the
  compounds molar mass.
• How do we calculate composition of a compound?

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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.

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Composition of Compound

• 1. What is the composition of each element in
  the following compound, Al(NO2)3 ?
• 2. What is the mass of Al in 6.5 g of Al(NO2)3 ?
  
• (Hint use composition data to solve problem)

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Mole Conversions 2 step Problems
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Bell Ringer Chemical Quantities

• 1. If a sample contains 2.34x1023 atoms of
  mercury, how much does it weigh in grams?

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Composition as a Conversion Factor

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Composition as a Conversion Factor

• What is the mass of Al in 6.5 g of Al(NO2)3 ?

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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?

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Bell Ringer Chemical Quantities

• How many grams are in 5.0 moles of Cs3N ?
• 2.How many moles are in 3.7x1021 cmpds. of NaCl?
• What is the composition of Cu2(SO4)?
• 4. How many grams of Cu are in 9.8 g of Cu2(SO4)?

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Infinite Campus Update

• Mole Conversion Lab 10pts.
• Chemical Reaction Lab Rough Draft 20pts.

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Formal Lab Reports Final CopyComputer Lab Days
Periods Wed. (4/25) Thurs. (4/26) Fri. (4/27) Mon. (4/30)
1st Library Library
2nd Library Library
3rd Rm 323 Rm 323
4th Rm 323 Rm 323
6th Library Library
7th Library
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Hydrate Lab
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Hydrate Lab

• Hydrate Cu(SO4) . H2O
• Anhydrous salt Cu(SO4)

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Mole Map
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Objectives

• Chemical Quantities Test today.
• Hydrate Lab tomorrow-read procedures
• Bring Chemistry Textbook tomorrow

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Chemical Quantities Test

• Choose one of the molar mass problems to
  calculate.
• Test A and B qts10. calculate composition of
  C16H18N2O4S omit qts. 12.
• Test C and D qts 10 caculate composition of
  Fe(CH3O2)2 omit qts. 11