RUST

Inner Workings

BACKGROUND RESEARCH

Summary:

Rust is an iron oxide that is created from exposure to oxygen and water. Over time, the oxygen combines with iron at an atomic level, forming the rust and weakening the actual iron the rust is formed on. (Pollick, “What is Rust?”) Oxygen (O) In the form of air or water takes electrons from the original iron (Fe) to form Iron III Oxide (Fe2O3). (McGraw Hill Education, 593) The formation of this new material is ana ionic bond between the iron and the oxygen as a form of synthesis (2Fe + 3O -> Fe2O3). This makes iron oxide somewhat polar. Since rust is an iron oxide, rust is a form of combustion and decay because the oxide breaks apart the original material to form the oxide. The rate at which the iron oxide forms can be dependent on the environment it is in, and the levels of moisture and temperature. The rate of rusting is mostly affected by moisture. The rate of rusting can be accelerated by amounts of water, especially if the water has a high number of electrolytes. (Vork, “How does Rust Spread?”) There is another factor as well- temperature. Atoms, ions, and molecules must collide to react, and because they are moving at a faster rate when heated, the more they collide, reacting faster, and vice versa. (McGraw Hill Education, 596) The more hot the environment gets, the better the rust can form. Since water and temperature manages to expedite the corrosion, how can it be slowed? Well, you could paint the iron, because layers of paint shut out the oxygen, making the rust slow down, or alloy it with other metals, like in steel. (Vedantu, “Methods of Prevention of Rusting of Iron”) Now knowing how rust is formed and how it works, does it matter? Does it have any pros or cons? The effects of rusting mainly includes damage to the original material. This can be a problem in airplanes or vehicles, electronics, and museum artifacts. (Camil, “What are the Effects of Corrosion?”) Anything that happens to contain iron in it, when exposed to iron and moisture, can rust. Rust prevention is quite a difficult task, and without protection or prevention the rust can easily break apart, and not only damage the original material but can be used to spread a disease called tetanus, if there is an exposed cut or bleed it can be contaminated with an overly-rusted material. Overall, rust is an iron oxide formed from interaction between oxygen and moisture on iron. The oxidization process can be sped up by water or temperature and prevented by layers of coating or alloying the metal.

PROBLEM STATEMENT

How does the time it takes for iron to rust differ in different environments?

PURPOSE

Understanding how iron rusts can have many industrial uses, such as having a product built for the outdoors, and making sure it doesn't decay, or creating an iron building and making sure it does not get all rusty. This can even be useful on other planets while trying to set up a building on the moon or mars, where the atmosphere can affect rust.

HYPOTHESIS

If the environment the iron is in contains more moisture and higher levels of oxygen, then the iron will rust faster because rust forms because of oxygen and moisture and having more of those levels will produce more rust.

MATERIALS

Material List:

-Iron Nails (5.08cm length)

-Environments (Indoors, Outdoors, Simulated Rain, Freezer, Submerged)

PROCEDURE

Procedure:

1.) Find an environment (different environment every five trials)

2.) Place five iron nails in environment (each nail is one trial)

3.) Wait three days, check back on iron nails

4.) Remove iron nails from environment

5.) Measure amount of rust qualitatively

Repeat steps 1-6 for 25 trials, five trials at a time.

VARIABLES

Variables:

Independent/Manipulated Variable:

The environment the iron is in

Dependent Variable/Respondent Variable:

The time it takes for iron to rust

Control Variables:

The time of day the iron is initially set out

The space between iron nails

The age of iron nails

The object iron is placed on

The content of the iron

PICTURES

During the experiment, many photos were taken. Here are pictures of the experiment.

Photo One

The 'Simulated Rain' category nails after the three days

Photo Two

The scientist placing the 'Submerged' category nails

Photo Three

The nails fresh out of the packaging

Photo Four

The 'Submerged' category nails after the three days

Photo Five

The 'Simulated Rain' setup to actually simulate the rain

DATA GRAPHS

Post-experiment, the data was recorded.

Click the pictures to view them in a fullscreen dialogue box.

DATA ANALYSIS

After the three days of the experiment, the data was recorded. The indoor, outdoor, and freezer all had no rust visible after the three days. The submerged category nails happened to have tiny splotches of rust growing outward from the nails, with some nails having more rust than others. The rain category nails all were fully rusted, or the parts that touched the hose water were, which is what the scientist counted. The overall trend in rusting happened to be that the environments that had more moisture in them ended up with more rust, if there was oxygen in the environment to form it. Therefore, the submerged category was an outlier- it would have been covered all over if not for the lack of oxygen inside of the water. The amount of rust on each nail per category happened to be very similar to each other, and that may be because the nails were all set out at the same time. The only outlier to this trend, yet again, is the submerged category. The dissolved oxygen in the water gave some more leverage towards some nails. Bubbles, pockets of oxygen, latch on to the nails closer to the surface, as dissolving always happens near the surface. Not only this, but the surface area allows more bubbles to form on said surface, and the nails that rusted first, near the surface, allowed more surface area for the bubbles to form. Overall, the results were quite consistent throughout categories, making the results very precise, however not as accurate as expected due to possible temperature low during the time of the experiment.

CONCLUSION

After the experiment of rusting nails for three days, the hypothesis was mostly accepted. The expected result was that the freezer and indoor categories would have gotten no rust whatsoever, and that is what happened in the actual experiment, which lined up to expectation. The expectation for the outdoor category was that it should have had some rust due to more moisture in the air, however, the outdoor category nails had no rust visible. The rain category nails were completely covered, and the submerged category nails had some rust. The surprising information was that the submerged category nails and the outside category nails were misaligned with the expectations. The expectations for the submerged category nails were that they would have no rust because no oxygen, but this was not the case due to the dissolved oxygen within the water that had enabled the oxygen to rust. In the outside category nails, the expectation was that it would have some rust, yet this was not the case, as the outside temperature was at a low for the three days. This brings the conclusion to the outside factors that could have skewed the results. There were no outside factors that were controllable by the scientist that affected the results. The only possible outside factors were weather and humidity, which are non-controllable. This could have enabled the outside category nails to have some rust, if the temperature was higher than it was on the days of the experiment, however it was cold outside on the three days, and that may have made the experiment results a little harder to read, but at the very least that explanation aligns with the background research. The overall trend of moisture that was noticeable also aligns with background research. If the experiment could be changed in any way to make it more fair, unbiased, or more conclusive, the weather should be changed. The temperature and humidity outside messed with the results more than it should have, and if changed, would make the experiment more worthwhile and unbiased and conclusive. Even though the experiment was technically fair due to uncontrollable outside factors, the 3/5 ‘no rust’ average does not sit well with what the expectation was, and the weather was the main problem. These results can be used in home or industrial rust protection as valid uses of the results, if the outside factors are recognized and accounted for. Knowing what forms rust, accelerates it, and prevents it can help prevent rust in the future. So overall, the hypothesis was, at most, mostly accepted.