CHEM 205 lecture 7

• Atom economy


  % atom economy = (MM desired product)/ (total MM of all reactants) x100%
• Stoichiometry


  1. Write balanced reaction equation

  2. Convert mass to moles (mass reactant à moles reactant à moles product à mass product)

  3. Set up mole ratio

  4. Use mole ratio to calculate moles of desired substance

  5. Convert moles to grams
• Limiting reactant


  The reactant that runs out first based on number of moles
• Excess reactant


  The one which is left over
• Aqueous solutions


  1. Identify species present in combined solution before reaction has occurred

  2. Write balanced equation

  3. Calculate moles of the reactants

  4. Determine which reactant is limiting

  5. Calculate moles of the product or products

  6. Convert to grams or other units
• Percent yield


  (actual yield)/(theoretical yield) x100%