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Take 7 test tubes and 11 clean nails. Prepare the tubes as shown below:
Tube 1: Put 2 clean nails in the test-tube and half cover them with distilled water. These
nails are in contact with air and water and form the control experiment.
Tube 2: Put a few pieces of anhydrous calcium chloride or silica gel in the bottom of a dry
test-tube, and also two nails. Put a plug of cotton wool in the top of the tube. These nails
are in contact with air, but not moisture.
Tube 3: Boil water for several minutes to expel dissolved air and pour into the test-tube
whilst hot. Put 2 nails in the water. Put a little Vaseline or a few drops of olive oil on the
surface of the hot water. The Vaseline will melt and form an airtight layer, solidifying as
the water-cools. These nails are in contact with water but not air.
Tube 4: Half cover 2 nails with water containing a little common salt dissolved in it. These
nails are in contact with air, water and salt.
Tube 5: Wrap a piece of zinc foil round part of a nail. Put the nail in the test-tube and
almost cover with tap water.
Tube 6: Wrap a piece of tin foil round part of the nail. Put the nail in the test-tube and add
tap water as you did for tube 5.
Tube 7: Wrap a piece of copper wire round a nail and put it in the test-tube exactly like
tubes 5 and 6. Stand these 7 test tubes in a rack and leave for several days. Note the
conditions for rusting and which metal, (zinc, copper or tin), is best at preventing rusting.
sharon kalunda answered the question on April 12, 2019 at 07:46
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