Material:   steel wool (90% iron)
                water
                vinegar
                bleach  ( avoid contact with the bleach!!)
                table salt
                5 saucers
                a flash light ( optional)

Experiment:    pour some water in the 5 saucers. Keep one saucer with water only.  To the second
                      dish add some bleach; to the third dish add some vinegar. To the fourth  dish add vinegar
                      and bleach and to the fifth dish add some salt.
                       Put a small amount of steel wool into each one.
                       Observe. One dish will show sign of rusting almost at once.
                      Another one will begin in a few minutes....keep the set up for three hours.
                      You may shine a flash light on the steel wool to better observe the formation of rust.

PLEASE PRINT THIS REPORT AND COMPLETE.  Name:____________________

1.  Rank the 5 saucers from the fastest rusting to the slowest:   _______________________
                                                                                             _______________________
                                                                                              _______________________
                                                                                              _______________________
                                                                                            ________________________
  2.Although the reactions involved in rusting are quite complex, the overall reaction is

                  ______        +      ________    +   _________    =    2   Fe2O3 . 3 H2O   (*)
                 iron                 oxygen gas               water              iron IIIoxide trihydrate

                                                                              
                        (*)  this formula of iron III oxide is attached to three molecules of water.You
                 have a total of 4 Fe,  12 O,  12 H.

  3.Going further:

      A. Determine the mass of iron III oxide trihydrate that you would prepare with 1 g iron.
 
 

                                                                                     ans:____________g.
 

        Calculate the number of moles of  O2 that react with 1 g of iron.
 

                                                                                      ans:___________moles

           Knowing that steelwool is 90% iron, calculate the mass of steelwool needed to get 1g of iron.
 

                                                                                      ans:_________g
 
 

       B. The mechanism of rust formation involves the migration of electrons. Note that
            the salt  doesn't enter into the rusting reaction above. Try to explain how
            it affects the rusting process.
 
 

            Why is salt  a major cause of rust formation on automobiles?
 
 
 
 

        C. Bleach is a solution of sodium hypochlorite;   write down the formula :______________
             It is called an oxidizer: how does it affect the rusting process?
 
 
 

 
        D. List three ways by which corrosion can be prevented.  ( TEXTBOOK)

                 1.     ____________________________________________________________

 
                 2.    ____________________________________________________________

 
                 3.    ____________________________________________________________
 
 
     Evidence    :  Now that you have done this extra effort, you are entitled to earn an
              additional 15 points  on your participation grade ( about 1 point on the grand total)  IF
                                    -- your answers are correct

                                    -- you bring the report  in class on or before october 31st!

                                    -- you staple a zip log bag containing some rusted steel wool