Final Results of Metals

Iron effected  by deoxygenated water

Iron effected by Oxygenated Water 

Sodium Chloride effected Nail

Iron effected by Warm Water

Iron effected by Cold Water

Aluminium effected by Oxygenated Water

Aluminium effected by Salt Water

Aluminium effected by Deoxygenated Water

Aluminium effected by Cold Water

                                                     Aluminium effected by Warm Water
                                                   

Aluminium effected by Warm Water 

Results Day 9 27/02/13

This was the last day of the investigation. The nails appear to have corroded an extreme amount since the investigation first started. The iron nails all corroded a large amount, with the Na Cl nail appearing to corrode the most, and the warm water and oxygenated water following behind. The deoxygenated water and cold water corroded the least, but significantly more than any of the aluminium metal pieces.

The aluminium has still proven to be very resistant to corrosion. However crevice corrosion has begun occurring on the surface of the aluminium metal placed in the warm water. The metal is quite thin, which resulted in the formation of small holes, in the middle of the metal. The sodium chloride aluminium metal had signs of galvanic corrosion occurring on the surfaces. 

Final Metal in Solution

Results Day 8 25/02/13

After coming back from two days of unrecorded data, the nails appear to have corroded an extreme amount in just this time. The sodium chloride solution, along with the warm water solution have corroded the most. Their solution is colored dark orange and dark amber and smaller amounts of rust are attached to the nail itself. Most corrosion is found in the solution. The NaCl nail is colored black, while the warm water nail is dark orange. The other solutions still have a spiral formation around the nail, with smaller amounts of flakey rust, floating within the solution. 

The aluminum has still proven to be extremely resistant to corrosion, as results have not changed extensively. 

Results Day 7 24/02/13

Data was not collected today as access to the labs was restricted due to the weekend.

Results Day 6 23/02/13

Data was not collected today as access to the labs was restricted due to the weekend.

Results Day 5 22/02/13

The iron metals continued rusting at fast speeds. The salt water solution is still appearing to be clearly rusting the greatest. The warm water solution was the second greatest, but the corrosion has slowed right down. The cold and deoxygenated solution nails are still continuing to rust the least. As for the Aluminium, very little rust has formed, and only occurring on the warm water solution. 

Results Day 4 21/02/12

The iron metals continued rusting at fast speeds. The salt water solution appears to be currently rusting the greatest, with the warm water not far behind. The cold and deoxygenated solution nails are rusting the least. As for the Aluminium, very little rust has formed, and only occurring on the warm water solution. 

Results Day 3 20/02/13

The metals continued rusting, slightly slower than that of the first 24 hours. The warm water and salt water solutions seemed to be rusting the greatest, while the cold and deoxygenated rusting the least.

Metals in Solutions After 2 days

Results Day 2 19/02/13

The nails have now been left in their solutions for 24hrs and corrosion appears to be occurring at both rapid and slower rates between the five environments. And also between the two metals of Aluminium and Iron. 

Metals in Solutions after 1 Day

Creating the Five Environments 18/02/13

Today, the solutions were created (Steps 4-7 of method). The oxygenated water environment consisted of distilled water, where 160mL was added to each of the four cups. The deoxygenated water environment was also made which had 140mL of oxygenated water, with a 20mL Oil layer covering the surface of the water. The warm water solution was created using 110mL of boiling water, mixed with 50mL of room temperature distilled water. The Salt water environment was created using 160mL of distilled water, with one teaspoon of sodium chloride added, and the cold water environment was created by using 100mL chilled water, combined with 60mL of room temperature water. These solutions were added to the cups labelled according to the solution, and left in the lab for signs of corrosion.

Equipment Used to Measure out Solutions

Five Environments Set Up

Setting up the Investigation 12/02/13

Steps 1-3 of the method were completed, where all the equipment was gathered and labelled and the nails were cleaned using steel wool. The nails and metal was weighed (in grams) and the salt water solution was formed.

             Preparing the Nails  

 
Weighing the Nails on Electronic Scales

Labeling Equipment and Placing the Metal Inside Cups

Initial Mass of Iron and Aluminium Metals:

Method 05/02/13

The method was constructed, and final preparations for the investigation were made. It was decided that I would place 2x 5 Iron Nails and 2x 5 Aluminium Strips in the five different environments (Oxygenated water, deoxygenated water, salt water, warm water and cold water) and compare the two different metals, along with comparing the nails within those environments. 

Method:

1.     Gather all required materials and equipment for the investigation and label all testing equipment accordingly

2.     Place the 20 plastic cups and place them on a scientific tray

3.     Weigh the pieces of Aluminium, along with the Iron nails and record their initial mass (in grams)

4.     Gather the ten identical iron nails and clean them using steel wool and place each into a separate plastic cup

5.     Gather ten aluminium strips, also cleaning them with steel wool, and place them into the remaining plastic cups

6.     Fill the cups half way full, filling each of the test tubes containing the iron nails, with room temperature oxygenated water, with salt water (by adding one tablespoon NaCl), with deoxygenated water (by adding two tablespoons of Oil), with boiling hot water and cooler water

7.     Fill the cups half way full, filling each of the test tubes containing the aluminium nails, with room temperature oxygenated water, with salt water (by adding one tablespoon NaCl), with deoxygenated water (by adding two tablespoons of Oil), with boiling hot water and cooler water

8.     Observe the colouring and structure of the iron and aluminium nails and make note of its appearance each day, recording the changes that the metals are going through

9.     After 12 days remove the nails from the solutions and weigh them. Record their finished mass and calculate that as a % Mass loss of each nail. 

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.

Research 01/02/13

More research was conducted regarding the five different environments of oxygenated water, deoxygenated water, salt water, warm water and cold water. It was found that oxygenated water forms an acidic solution when added to a metal, and allows the oxidation process to occur more easily than that of moist air (Larson, 2007). Oxygenated waters forms when hydrogen reacts with oxygen and can be expressed through the following equation: 2H₂ + O₂  → 2H₂O. It was also found that deoxygenated water forms a protective layer coating on the surface of the liquid, which protects the oxidation/reduction reactions from occurring and protects metal from corrosion. Salt was found to be a main accelerant in the corrosion processes due to the NaCl compound breaking up into Na+ and Cl- ions, with charges that are free to move. Warm water has a similar effect, where the particles are more active at this temperature and therefore react more easily. This also means that cold water will not react as easily, and therefore will not corrode as much as warm water does. 

Also, research showed that when Iron corrodes, rust is formed. And when Aluminium corrodes, galvanic, pitting or crevice corrosion will occur. These processes are both quite similar in that they follow the oxidation/reduction processes, however, these types of corrosion all affect the metals differently, which will be investigated through this EEI.