SCIENTISTS COME TO CHEMISTRY CLASS

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SCIENTISTS COME TO CHEMISTRY CLASS
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Journal

• How many words can you get out of the word
• STOICHIOMETRY

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Gram Formula Mass

• Example
• NaCl is Na22.99 Cl35.45 so the total is
  58.48 for NaCl

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Gram Formula Mass

• Example Ca(OH)2 is one Ca or 40.08, two oxygens
  or 32.00 and two hydrogens or 2.02 for a total of
  74.10 gram molecular mass

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THE MOLE

• What is it?
• Avogadro who?
• Why do I need it?
• How does it relate
• to molar mass?

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The Chemistry Mole!
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THE MOLE

• What is it?
• Avogadro who?
• Why do I need it?
• How does it relate
• to molar mass?

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What is it?

• 12 GRAMS OF CARBON-12 CONTAIN
• 1 MOLES WORTH OF

ATOMS, MOLECULES, FORMULA UNITS
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THE MOLE

• What is it?
• Avogadro who?
• Why do I need it?
• How does it relate
• to molar mass?

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COUNT LORENZO ROMANO AMEDEO CARLO AVOGADRO

• 1.00 MOLE ALWAYS MEANS
• 6.O221 X 1023
• ATOMS, MOLECULES
• OR FORMULA MASSES
• THIS IS KNOWN AS AVOGADROS NUMBER

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Which one is Avogadro?
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THE MOLE

• What is it?
• Avogadro who?
• Why do I need it?
• How does it relate
• to molar mass?

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Why do I need it?

• This is a way to provide an easier way to use
  massive numbers
• The word MOLE in Latin means massive heap the
  little critter that invades our lawn leaves
  massive heaps of soil after him
• HOW MASSIVE?

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MASSIVE MEANS?

• If you won 1 mole of dollars in a lottery the day
  you were born and spent a billion dollars a
  second for the rest of your life, you would still
  have more than 99.999 of the prize money left
  when you died at 90.

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OR.

• 1 MOLE OF CHEMISTRY
• TEXTBOOKS (YEAH !)
  WOULD COVER THE SURFACE OF THE
  EARTH TO A HEIGHT OF ABOUT 300 KM OR AROUND
  480 MILES

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How many Chemistry Textbooks?
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THE MOLE

• What is it?
• Avogadro who?
• Why do I need it?
• How does it relate
• to molar mass?

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What is molar mass?

• The atomic mass of any element, expressed in
  grams ,
• IS
• 1 mole of that substance

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REMEMBER.

• THE MOLAR MASS OF AN ELEMENT IS EQUAL TO ITS
  ATOMIC MASS,
• EXPRESSED IN
• !!!! GRAMS/MOLE !!!!!

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CATCH THE MOLE
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USING MOLES

• UNIT FACTORING IS THE BASIS OF USING THE MOLE
  ALWAYS USE THESE 2 STEPS

• STEP 1 ALWAYS SHOW YOUR UNITS

• STEP 2 ALWAYS SHOW YOUR UNITS CANCELLING

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USING MOLES CONT

• STEP 3 START WITH YOUR GIVEN UNIT

• REVIEW
• 1. STATE ALL UNITS
• 2.SHOW ALL CANCELLING
• 3. START WITH YOUR GIVEN UNIT
• 4. SET UP THE PROBLEM SO GIVEN CANCELS AND
  WANTED STAYS

• STEP 4 CANCEL THE GIVEN AND KEEP THE UNIT WANTED
  USING MOLAR MASS

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REMEMBER -

• YOU CAN USE MOLAR MASS
• (ATOMIC MASS IN GRAMS)
• 1 MOLE
• TO EITHER MULTIPLY WITH OR DIVIDE WITH,
  DEPENDING ON WHICH UNIT YOU WANT TO KEEP

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REMEMBER -

• 1 moleatomic mass so.
• 1mole or atomic wt.
• At.wt. 1 mole

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USING MOLES TO SOLVE PROBLEMS

• A SCIENTIST NEEDS .300 MOLES OF CHLORINE.
• A TANK CONTAINING 15 GRAMS OF CHLORINE IS
  AVAILABLE.
• IS THAT ENOUGH?

• YOUR GIVEN IS ACTUALLY GRAMS ISNT IT? LETS
  CANCEL OUT THIS UNIT WITH MOLAR MASS
• YOUR NEEDED UNIT IS MOLES SO YOU CAN COMPARE IT
  TO THE .300 MOLES THE SCIENTIST NEEDS

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• MOLES OF Cl ATOMS
• 15g Cl 1 mol Cl
• 35.45g Cl
• 0.423 mol Cl
• How many did he need? (.300 moles)
• Does he have enough?
• THIS TYPE OF PROBLEM IS GOING FROM MASS (OR
  GRAMS) TO MOLES

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NOWTRY THIS PROBLEM

• A 0.279 G SAMPLE OF IRON IS HEATED AND ALLOWED TO
  REACT WITH OXYGEN FROM THE AIR. HOW MANY MOLES OF
  IRON IS THAT?
• (this is a mass-to-mole problem)

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CHECK YOUR CALCULATIONS

• MY GIVEN IS GRAMS, SO ILL WANT TO CANCEL THEM
• MY WANTED (OR NEEDED) IS MOLES, SO ILL WANT TO
  KEEP THEM
• ILL DIVIDE BY MOLAR MASS

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DID YOU GET IT CORRECT?

• A 0.279 G SAMPLE OF IRON IS HEATED AND ALLOWED TO
  REACT WITH OXYGEN FROM THE AIR. HOW MANY MOLES OF
  IRON IS THAT?
• 0.279 g Fe 1 mol Fe 0.005
• 55.85g Fe mol Fe

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Whats Reacting with what?
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HOW ABOUT A MOLE TO MASS TYPE OF PROBLEM?

• YOU HAVE MOLES, YOU NEED GRAMS.
• HOW ABOUT HAVING 3.02 MOLES OF Zn(PO4)2, AND
  FINDING GRAMS?
• 3.02mol Zn(PO4)2 255.33g Zn(PO4)2
• 1 mol Zn(PO4)2
• 772.40g Zn(PO4)2

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RUN THIS ON YOUR CALCULATOR

• HAVING 2.5 MOLES OF NaCl GIVES YOU HOW MANY GRAMS?

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CHECK YOUR CALCULATIONS

• MY GIVEN IS 2.5 MOLES ( LETS CANCEL OUT THIS
  UNIT)
• I WANT GRAMS ( LETS KEEP THIS UNIT)
• SO ILL MULTIPLY BY THE MOLAR MASS

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DID YOU GET IT RIGHT?

• HAVING 2.5 MOLES IS HOW MANY GRAMS?
• 2.5 mol NaCl 58.45g NaCl
• 1 mol NaCl
• 146.13 g NaCl

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Dealing with Atoms?????

• You can also convert from atoms to moles and
  moles to atoms using an equivalent relationship

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Dealing with Atoms?????

• Remember that 1 mole 6.02 x 1023 amount of
  atoms or molecules

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Dealing with Atoms?????

• So..
• 1 mole 6.02x1023
• 6.02x1023 1 mole
• Can be used as conversion factors

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Dealing with Atoms?????

• 2.0 moles 6.02x1023molecules
• 1 mole
• 1.20 x 1024

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Back to the Textbooks Ready?
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NOW TO ADD THE LAST STEP STOICHIOMETRY

• KEY IDEA
• MOLES COEFFICIENTS
• OF A BALANCED
• CHEMICAL
• EQUATION

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STOICHIOMETYRY

• 2 NO O2 2 NO2
• Actually reads as
• 2 moles of NO plus
• 1 mole of O2 equals
• 2 moles of NO2

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Stoichiometry to the Rescue

• 2NO O2 2NO2
• I CAN COMPARE MOLES OF NO TO MOLES OF NO2
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• OR
• I CAN COMPARE MOLES OF O2 TO MOLES OF NO2
  12

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ANOTHER WAY TO SAY IT

• 2 MOLES NO
• 2 MOLES NO2 AND
• 2 MOLES NO2
• 2 MOLES NO

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AGAIN

• ALSO TRUE WOULD BE
• 1 MOLE O2
• 2 MOLES NO2 AND
• 2 MOLES NO2
• 1 MOLE O2

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NOT MOLE RATIOS !!!

• THESE COMPARISONS ARE CALLED MOLE RATIOS
• YOU CAN USE THEM RIGHT SIDE UP OR UPSIDE DOWN

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HOW DO I USE A MOLE RATIO?

• MOLE RATIOS LET US SWITCH FROM A REACTANT TO A
  PRODUCT IN A CHEMICAL EQUATION
• THEY DO THIS BY ACTING AS A CONVERSION UNIT (
  like molar mass does)

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FOLLOW THE UNITS

• N2 O2 2NO
• How many moles of NO will we get out of 2.25
  moles of N2?
• 2.25 moles N2 2 mol NO
• 1 mol N2
• 4.50 mol NO

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FOLLOW THE UNITS

• N2 O2 2NO
• 2.25mol 4.5mol
• 2.25 moles N2 2 mol NO 4.5mol
• 1 mol N2
  NO
• NOTICE, THE MOLE RATIO SWITCHED US FROM N2
  NO

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TRY THIS..

• GIVEN 2 C O2 2CO
• HOW MANY MOLES OF CO ARE PRODUCED FROM 2.50 MOLES
  OF CARBON?

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Check your calculations

• GIVEN 2 C O2 2CO
• HOW MANY MOLES OF CO ARE PRODUCED FROM 2.50 MOLES
  OF CARBON?
• 2.50 mol C 2 mol CO 2.50 mol CO
• 2 mols C
• Moles reactant Moles product

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Last step in STOICHIOMETRY

• SINCE WE KNOW HOW TO GO FROM GRAMS TO MOLES AND
  FROM MOLES TO GRAMS USING THE MOLAR MASS, AND WE
  CAN GO FROM GRAMS REACTANT TO GRAMS PRODUCT
  USING THE MOLE RATIO

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STIL LAST STEP IN STOICHIOMETRY

• WE CAN NOW GO FROM MASS TO MASS
• MEANING WE CAN GO FROM THE MASS OF A REACTANT TO
  THE RESULTING MASS OF A PRODUCT!

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HERE ARE THE STEPS

• 1. CONVERT GRAMS REACTANT TO MOLES OF REACTANT
  (MM)
• 2. CONVERT MOLES REACTANT TO MOLES PRODUCT (MR)
• 3. CONVERT MOLES PRODUCT TO GRAMS PRODUCT (MM)

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HERES WHAT I MEAN

• 3 FeO 2 Al 3 Fe Al2O3
• 14.4g ?g
• Step 1 grams to moles
• 14.4gFeO l mol FeO 0.20 mol FeO
• 71.85gFeO

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HERES WHAT I MEAN

• 3 FeO 2 Al 3 Fe Al2O3
• 14.4g ?g
• Step 2 moles FeO to moles
• Al2O3
• .20molFeO 1 mol Al2O3 0.067mol
• 3 mol FeO Al2O3

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HERES WHAT I MEAN

• 3 FeO 2 Al 3 Fe Al2O3
• 14.4g ?g
• Step 3 moles of Al2O3
• to grams of Al2O3
• .067mol Al2O3 101.96g Al2O3
• 1 mol Al2O3
• 6.83 g

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Now try some STOICHIOMETRY for yourself

• CALCULATE THE MASS OF TITANIUM (IV) CHLORIDE
  PRODUCED FROM THE REACTION OF 1.25g OF TITANIUM
  METAL AND CHLORINE GAS

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Now try some STOICHIOMETRY

• CALCULATE THE MASS OF TITANIUM (IV) CHLORIDE
  PRODUCED FROM THE REACTION OF 1.25g OF TITANIUM
  METAL AND CHLORINE GAS
• Wheres our balanced chemical equation?
• Ti (s) 2Cl2 (g) TiCl4 (s)

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Now try some STOICHIOMETRY

• NOW WE CAN PROCEED
• Ti (s) 2Cl2 (g) TiCl4 (s)
• 1.25g ?g
• Step 1. g moles (mm)
• 1.25g Ti 1 mol Ti .026mol
• 47.88g Ti Ti

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Now try some STOICHIOMETRY

• NOW WE CAN PROCEED
• Ti (s) 2Cl2 (g) TiCl4 (s)
• 1.25g ?g
• Step 2.mol Ti mole TiCl4 (MR)
• .026mol Ti 1 mol TiCl4.026mol
• 1 mol Ti TiCl4
  

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Now try some STOICHIOMETRY

• NOW WE CAN PROCEED
• Ti (s) 2Cl2 (g) TiCl4 (s)
• 0.026moles ?g
• Step 3. mol TiCl4 g TiCl4 (MM)
• .026mol TiCl4 189.88g 4.94g
• 1 mol TiCl4 TiCl4

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Orthe all in one step method of MASS TO MASS

• STEP 1 STEP 2 STEP 3
• 1.25gTi 1 mol Ti 1mol TiCl4 189.68gTiCl4
• 47.88gTi 1mol Ti 1 mol TiCl4
• (MM) (MR) (MM)
• 4.94g TiCl4
• WE WENT FROM MASS OF A REACTANT TO MASS OF A
  PRODUCT! ARENT WE CHEMISTS!!!!!!!!!!!!!!!!!!!!!!
  !!!!!!!

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All it takes is your textbook and your effort!
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Pop Reading Quiz

• Given
• 2C O2 2CO
• How many moles of O2 are produced from 2.5 moles
  of C?
• How many moles of CO react with 2.50 moles of C?

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Correct your neighbors paper

• 2C O2 2CO
• 2.5mole C 1 mole O2 1.25 mol O2
• 2 mole C
• 2.5 mole C 2 mole CO 2.50 mole CO
• 2 mole C