Investigating the chemical behaviour of metals

Apparatus

These pieces of equipment will be needed to carry out my experiment, to a good standard:

• Test tubes (x15)
• Test tube rack
• Acid (hydrochloric acid)
• Alkaline (sodium hydroxide)
• Water
• Different metals (zinc, aluminium, copper, iron, magnesium)
• Pipette
• Measuring cylinder

Safety

• Make sure that when dealing with the acid, handle it with care. The reason for this is that if it goes on your skin or somebody else skin it could be corrosive to some of the skin and could cause irritation.
• Always wear gloves and goggles so that if the acid drops, it would not drop on your hand or splatter in your eye.
• Also alkaline is present so the same problems that can occur with the acid to the skin can happen with the alkaline.

Method

• First collect the materials
• Then place one of your metals e.g. zinc, in three test tubes.
• In one of the test tubes place 20cm3 of water, then in the second place 20ml of alkaline, then place 20cm3 of acid in the third. Make sure that you get a reading of how much you are putting in so that it is a fair test.
• Do this with the other metals placing them each in the different substances.
• Then take your first reading, and record it.
• Wait for a week and then take your second reading.
• And then do the same wait for a week and then take another reading.
• Write the results in a table.

Results

Discussion

Looking at all the metals the least reactive metal is copper. In the water the metal did not react at all, this is what I expected as all water pipes are made of copper. The most reactive metal is magnesium. Another metal that has reacted to the chemicals is iron. The metal rusted in two of the chemicals.

Looking at what metals would be the best to use as an ice skate blade, the best would be copper as it was the least reactive, but the metal is too soft.

If that is the case then a combination of metals, iron could be used as a main part of the blade and then coat it with copper. That way the skate will be strong but it won’t be that reactive.

Looking at the results of aluminium I was quite surprised as the metal did not react more. The reason for this could be that when aluminium and oxygen combine it then becomes aluminium oxide therefore making the metal impermeable; hence no further reaction can occur. Aluminium could have reacted because the outer layer came off and then it reacted, and aluminium is extremely reactive.

Evaluation

Looking back at the experiment as a whole I think that it was a good experiment. I also feel that the results that I have achieved are fairly accurate. But I do not think that these results would be good enough for the industries. My reason for this is that my tutor commented on my results and said that one or two of them are unusual and the way they have reacted was unusual, this could have been from contamination during the experiment while I might have been away or contamination to the metals before they were handed to me. Another reason for this could be that some of the equipment may not have been sterilised before they were used. If this experiment had been carried out in the industries then maybe the results would have more accurate and the description given by the workers would have been more accurate and more detailed.