Stoichiometry

1
Stoichiometry

• Warm up questions..
• 1. Balance the following equation.
• Cu AgNO3 g Ag Cu(NO3)2
• 2. What is the mass of 4.65 moles of Cu(NO3)2?
• Today.What is a mole ratio and how is it used?

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Stoichiometry Mole Ratios

• Stoichiometry calculations of quantities in
  chemical reactions
• Its like bookkeeping for chemistry
• Baking..
• Making tricycles..

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• Balanced equations provided a wealth of
  information about reactions
• Atoms, molecules, moles of substances, and masses
• Bal. Eq. are essential for all calculations
  involving amounts of reactants and products
• If you know the of moles of one substance, a
  bal. eq. allows you to determine the of moles
  of all other substances in the reaction.

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• N2(g) 3H2(g) g 2NH3(g)
• What does this equation tell us?
• Moles of reactants and products can be related to
  each other
• Mole Ratio a ratio of the coefficients in a
  balanced equation
• 1 mol N2 3 mol H2 2 mol NH3
• 3 mol H2 2 mol NH3 1 mol N2
• This allows you to convert between different
  chemicals in a reaction

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• Steps
• 1. Write balance the equation
• Watch for diatomic elements
• 2. Set up the bracket with the value given
• 3. Convert starting number to moles if needed
• 4. Set up mole ratio in bracket to convert to
  moles of new substance