Stoichiometry

1
Stoichiometry

• Calculations of quantities in chemical reactions.
• The use of ratios to calculate quantities

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The five step process

• 1. Start with the balanced equation
• 2. Set up the problem - put down the tracks
• 3. Convert to moles if needed. This means you
  would be given grams, representative units or
  liters.
• 4. Convert to moles of what you want. You will
  use the mole ratio from the balanced equation.
• 5. Convert to what you are trying to find (grams,
  liters, representative units) if needed.

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Stoichiometry Example Problem 1

• How many moles of ammonia are produced when 0.60
  mol of hydrogen reacts with nitrogen?

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Stoichiometry Example Problem 2

• Your Turn
• How many moles of aluminum sulfide are produced
  when 1.2 moles of aluminum reacts with sulfur?

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Stoichiometry Example Problem 2

• Answer
• 2Al 3S --gt Al2S3
• 1.2 mol Al 1 mol Al2S3
• 2 mol Al
• 0.60 mol Al2S3

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Stoichiometry Example Problem 3

• How many grams of ammonia will be produced by
  reacting 5.40 g of hydrogen with nitrogen?

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Stoichiometry Example Problem 4

• Your Turn
• How many grams of aluminum are needed to react
  with 2.45 g of copper (II) chloride?

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Stoichiometry Example Problem 4

• Answer
• 2Al 3CuCl2 --gt 2AlCl3 3Cu
• 2.45 g CuCl2 1 mol CuCl2 2 mol Al
  27.0 g Al
• 134.5 g CuCl2 3 mol CuCl2 1 mol Al
• 0.328 g Al