Aim/Hypothesis 04/02/13

From the research carried out, the aim and hypothesis was able to be constructed (which is as follows):

Aim:

The Environment of the Metals

To investigate the effects that the five different environments of oxygenated water, deoxygenated water, sodium chloride in water, warm water and cold water, have on Aluminium and Iron, and to investigate which environment is least and most corrosive by degradation and appearance. 

The Type of Metal

To investigate the durability of Aluminium and Iron and to compare the amount of corrosion between the metals and to also compare the appearance of each metal during the corrosion stages.

Hypothesis:

It is predicted that the iron nail in the salt-water environment will corrode at the fastest speed and at the highest intensity. This is because salt is hygroscopic, meaning that it is able to attract water molecules toward the metal, allowing it to corrode due to the water. And also because the Na⁺ and Cl^- ions are free to move and react with each other when placed in water, which causes an increase in the rate of corrosion and speeds up the oxidation and reduction processes. The iron nail in the highest temperature environment will corrode at a similarly high speed to that of salt-water, because the energy is greater at a higher temperature, allowing for the oxidation reactions to take place more easily. This meaning that oxygenated water at room temperature will have slightly less corrosion than that of a higher temperature, and even less with lower temperatures. It is predicted that the iron nail placed in the deoxygenated water environment (with an oil layer) will not rust because the layer of oil maintains the absence of oxygen in the water, which prevents the metal from rusting and from a reaction taking place.

It is predicted that the aluminium will not corrode as easily as that of an iron nail, when placed in the same environments as the iron nails. The salt-water solution will be the only solution strong enough to begin to cause an effect of corrosion, due to the properties of resistance that this metal has.