Stoichiometry

• Stoichiometry: The study of the mass and amount relationship between products and reactants in a chemicals reaction
• Mole ratio: The amount ratio between one chemical and another from a chemical equation
• Stoichiometry used...

  • The ensure right products made
  • Right amount of reactants
• Stoichiometric amount: The amount of a chemical is proportional to its coefficient in a chemical equation
• What is the conversion process when given mass in a stoichiometry problem?

  Mass-->Moles-->Moles--> Mass
• Limiting reagent: The reactants that runs out FIRST
• Excess reagents: Reactant that is left over after a reaction is finished
• LIMITING reagent determines the amount of products made!
• Why do we use Limiting and excess reagents?

  • Cost efficiency
  • Ensure reaction completion
  • Environmental
  • Neutralization/bioremediation
  • Fuel efficiency
• Why are precent yields lower than 100%?

  • Competing side reactions
  • Experimental errors
  • Nature of reaction (environment)
  • Impurities in reactancts
• Precent yield: The ACTUAL amount of product produced
• Theoretical yield is the PREDICTED yield from calculations