Stoichiometry

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Stoichiometry

• Chapter 9
• Limiting reagents

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In Stoichiometry We work in moles.We cannot
calculate grams of product from grams of reactant
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Step 1 Grams of reactant to moles of
reactantStep 2 Moles of reactant to moles of
productStep 3 Moles of product to grams of
product
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Review

• Converting mass to moles divide grams by molar
  mass
• Converting moles to mass multiply moles by molar
  mass
• Converting moles to particles multiply moles by
  6.02 x 1023
• Can you go from mass to particles?

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Limiting Reagents
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Limiting Reagents a video

• http//wps.prenhall.com/wps/media/objects/439/4499
  69/Media_Portfolio/Chapter_11/Limiting_Reagent.MOV
  

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Theoretical Yield

• This is the amount of product expected in a
  perfect world with the amount of reactant given.
• In Limiting reagent problems, you find the amount
  each reactant would produce with no other
  constraints. That is two or more calculations
  depending on the number of reactants.
• The reactant that forms the least amount of
  product in its theoretical yield is the limiting
  reagent.

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How to do these problems

• First write a balanced chemical equation.
• Find the molar mass of each player be it
  product or reactant. (coefficients are not used
  to calculate molar mass)
• Convert the mass of each reactant given to moles.
  Grams divided by grams/mol.

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How to continued

• Find the molar ratio to convert moles of reactant
  to moles of product. (This is where you use
  coefficients)
• Convert moles of product to grams of product.
• If this is a limiting reagent problem, repeat for
  the other reactant and compare results.
• If you can add, subtract, divide, and multiply,
  you can do this!!

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