chp#01

• Stoichiometry


  Calculation of relative amounts of reactants or products using balanced chemical equations
• Molar mass


  Mass of one mole of a substance
• Molar mass calculation


  • H2SO4
  • Ca3(PO4)2

  
• Moles calculations


  Balancing of chemical equations
• Stoichiometry is based on the law of conservation of mass

  
• Assumptions of stoichiometry


  • All reactants are completely converted to products (irreversible reaction)
  • No side reactions occur
• Mole-mole relationship


  Moles of reactants and products are related by the balanced chemical equation
• Mole-mole relationship examples


  • Methanol burning in oxygen
  • Nitrogen and hydrogen producing ammonia

  
• Mass-mass relationship example


  • Iron production from iron ore

  
• Molar volume


  Volume of any ideal gas at standard temperature and pressure (22.414 dm3 or 22414 cm3)
• Molar volume examples


  • 2 g hydrogen = 1 mole = 22.414 dm3
  • 32 g oxygen = 1 mole = 22.414 dm3
• Molar volume calculations


  • Volume of 2.5 moles of chlorine at STP

  
• Limiting reactant


  Reactant that is completely consumed and limits the amount of product formed
• Reactant in excess


  Reactant that is not completely consumed and has some amount left over
• Determining limiting reactant


  • K2Cr2O7 and H2SO4 reaction
• Calculating mass of product and unreacted reactant

  • K2Cr2O7 and H2SO4 reaction

  
• Calculating number of molecules, ions, and ion mass

  • Ionization of H2SO4

  
• Calculating mass of product from reactant masses

  • Mg and S producing MgS
• Theoretical yield


  Amount of product calculated from balanced equation
• Actual yield


  Amount of product actually produced
• Percent yield


  Ratio of actual yield to theoretical yield x 100
• Reasons actual yield may be less than theoretical yield
• Calculating percent yield


  • CuSO4 and Zn producing Cu
• Calculating theoretical yield, actual yield, and percent yield

  • CH4 and Cl2 producing CCl4