Breadetaer
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### "Rusting Out" - How to find the rate of corrosion

Hi!
I am also doing the "rusting out" experiment, but with a few add-ins of my own.
My experiment is going to be testing the effect of household acids and bases on the rate of corrosion.
However, I am confused on the temperature thing as well. So, after we let the steel wool sit in the substance for a short period of time, we take it out and check its temperature and divide that by the time it took to get the rate of corrosion? or do we take its temperature before and after we submerge it and divide that by the time?

Thanks!

PS: Do bases really have any affect on the rate of corrosion? And how can I relate this to a real world application? (Maybe it can help people make their steel materials work after rusting over?)

SciB
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Occupation: Retired molecular biologist, university researcher and teacher

### Re: "Rusting Out" - How to find the rate of corrosion

Hi,

Your questions sound like they might better be answered on the Physical Sciences forum, but I'll take a stab at them since I am a chemist as well as a biologist.

I read the instructions for the corrosion project and you need to record the temperature before you do the experiment so you know what the degree of change is after the steel wool is exposed to a solution: https://www.sciencebuddies.org/science- ... #procedure

Testing Your Rain Models

Have your thin kitchen towel and plastic cup nearby.
Thread the rubber stopper onto the thermometer probe, as shown on the right side of Figure 4.
Place the rubber stopper, with its attached probe, inside the test tube. Record the temperature of the thermometer in your lab notebook. This will be your temperature at "time equals zero."

The rate of the reaction would be the change in temperature over the time interval, but according to the procedure, the temperatures are simply plotted against time. The temperature you record at the beginning of the experiment is your zero time-point on the x-axis. If you use a graphing program to plot the temperature results you can have it calculate the slope of each line. The greater the slope, the faster the reaction.

As to your last question about the effects of pH >7.0, basic solutions on iron--there's no reaction that I can recall. But, since acids promote oxidation I would guess that creating a basic environment might reduce the rate of rusting. I can't see how you would do that, however, since rain is acidic. Preventing exposure of the iron to oxygen with paint or oil seems to be the best method for now. I know if I don't keep my tools oiled they rust very quickly.

Hope this answers your question. You could try posting it on the Phys Sciences forum if you haven't done that already.

Sybee

Moderator: I've moved this topic to the Physical Sciences forum. Thanks!

Breadetaer
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Joined: Sat Oct 14, 2017 10:38 am
Occupation: Student

### Re: "Rusting Out" - How to find the rate of corrosion

Thanks!
I have just one more question. Will the temperature of the steel wool change at all within the 15 minutes after exposure to the acid/base? Since rusting takes some time, will the temperature given off by the reaction change quickle or slowly?

Thanks

Breadetaer
Posts: 7
Joined: Sat Oct 14, 2017 10:38 am
Occupation: Student

### Rusting out! Temperature change and rusting

Hi!,
I am doing the Rusting Out experiment (https://www.sciencebuddies.org/science- ... -corrosion), and I was wondering-
The procedure says to let the steel wool sit in the acid for 30 seconds, and then remove it. Then we are supposed to check its temperature once every minute for 10 minutes. My Question it, will the temperature even change within those short 10 minutes? Rusting is a long process, and the temperature changing dramatically in 10 minutes seems unlikely.
Thanks, -BreadEtaer

ultramatt
Student Expert
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### Re: Rusting out! Temperature change and rusting

Hey Breadetaer,

You're definitely correct in saying that rusting is a long process, but when steel comes into contact with water or a pH solution, it will start to oxidize. While you may not necessarily see a noticeable change in the color of the steel, you should definitely see a slight change in temperature.

Hope that helps!

-Matthew

Breadetaer
Posts: 7
Joined: Sat Oct 14, 2017 10:38 am
Occupation: Student

### Rusting out! Rusting, steel wool, and temperature changing within 10 minutes.

Hi!,
I am doing the Rusting Out experiment (https://www.sciencebuddies.org/science- ... -corrosion), and I was wondering-
The procedure says to let the steel wool sit in the acid for 30 seconds, and then remove it. Then we are supposed to check its temperature once every minute for 10 minutes. My Question it, will the temperature even change within those short 10 minutes? Rusting is a long process, and the temperature changing dramatically in 10 minutes seems unlikely.
And if the temperature changes, will it change enough for me to draw a conclusion?

On an unrelated note, would a regular kitchen thermometer, used typically to measure the temperature of meat, work on steel wool?
Thanks, -BreadEtaer

MadelineB
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### Re: "Rusting Out" - How to find the rate of corrosion

Hello BreadEtaer,

Please keep all your questions in the same topic, that way, the expert(s) who have been helping you can follow the thread and continue to help you more efficiently.

Thank you.
Moderator

Breadetaer
Posts: 7
Joined: Sat Oct 14, 2017 10:38 am
Occupation: Student

### Re: "Rusting Out" - How to find the rate of corrosion

Hi
I have another question. When i placed the steel wool in vinegar, the temperature didn't go as far down as it did when i placed the steel wool in water. However, if vinegar is an acidic substance and water is neutral, shouldn't the steel wool's temperature drop more when exposed to vinegar?

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