1. How many water molecules are in one mole of water ?  


                   6.02 x 1023  


2. What is the mass, in grams, of one mole of water ?  

                     18 grams 


3. What is the mass in grams of one water molecule ?  


                   3 x 10-23 g 


4. Perform the following operations: 

        1 mole of Fe =  55.8  g Fe 
        1 mole of CCl4  =  154  g CCl4  
        0.023 mole of NaCl =  1.35  g NaCl 
        6.5 g of HF =  0.325  mole of HF 

5. Give the atomic masses of the following elements.  


       H      C       O       Cl      Cu      U 
      1.0    12.0    16.0    35.5    63.5    238.0 


6. Compute the molecular masses of the following substances.  


                  CO2       HClO3         S8  
                 44.0        84.5        256.8 


7. Compute the mass of one mole of each of the following 
   substances.  


           Cu     O2  C12H22O11  Al2O3  
          63.5g   32.0g     342.0 g       102.0 g 


8. Lime, calcium oxide (CaO), is prepared industrially by the 
   thermal decomposition of limestone, calcium carbonate (CaCO3).  
   Carbon dioxide is also produced in this reaction.  Write a 
   balanced reaction equation for this decomposition.  


                 CaCO3 ---> CaO + CO2(g) 


   Calculate how many grams of lime can be made from 275 g of 
   limestone using this reaction.  


    275 g CaCO3 is 2.75 moles of CaCO3. CaO is produced at the 
    rate of one mole for each mole of CaCO3 decomposed.  
    Therefore, 2.75 mole of CaCO.3. will produce 2.75 mole of CaO.  
    The formula unit mass of one mole of CaO is 40+16 = 56 g.  
                 56g * 2.75 mole = 154 g of CaO 


9. Sulfuric acid, H2SO4, is made industrially by the reaction of 
   sulfur trioxide (SO3) with water.  Write a balanced reaction
   equation for this process.  


                       SO3 + H2O ---> H2SO4  


   Calculate how many grams of sulfur trioxide are required to make 
   75 g of sulfuric acid using this reaction.  


    One mole of sulfur trioxide will produce one mole of H2SO4.  
    The molecular mass of H2SO4 is 2x2+ 32 + 4x16 = 98g.  75 g is 
    equal to 0.76 mole.  Therefore, 0.76 mole of SO3 is needed.  
    0.76 mole of SO3 has a mass of 61 g.