Rusting Nails student experiment and research

A. Hi, girls. Even though you're only in 6th grade, I think the point of your effort is to gain practice on how to proceed with such projects.

The first step is to make a lab book. This can be an inexpensive composition book.
but preferably the pages don't rip out. Then you number the pages. Now write everything you do in this one book, in ink, accurately recording everything you did and saw, and periodically writing the date and time.

So what kind of nails did you use? How much water? What did you see? Did both nails rust, neither rust, or did one set rust faster? Did any sediment accumulate in either jar? Did the color of the solution turn rusty or otherwise change?

You never erase because these are your observations. Your interpretation of what they mean may change as you study more and continue the experiment, but nothing can ever change what you observed. If you wrote something that you decide should not have been written because it's not an observation, you strike it through once, to show that it is to be ignored, but you leave it legible because lab results must never be altered.

Your town or county library has books on corrosion and I think the librarian would be happy to help you find something age-appropriate. Good luck.

A. Anna, what is pure water. If it is tap water, it has to have something else in it or the seawater would rust it faster. If you are using DI water, it would gradually eat some of the zinc off of the nail. If you are using zinc plated nails, vinegar should be faster as it will eat some of the zinc off. You also have to be extremely careful to treat all of the nails exactly the same way.

For tap water, carbon dioxide will react with the water to for a weak acid. Boil it first and the rate of acid formation will go way down, especially if you cover the container. Also the nails can not touch each other and really should be one to a container. They should be in a test tube or similar so they do not lay on the bottom. For pure water, I would use a distilled water that has not been ozone treated if you can get it. Boil this also. Temperatures of each tube must be identical. A water bath works well for this where at least half of the tube is submerged.

A. My hypothesis is that it will rust most at the waterline. Is that your hypothesis as well, Joanna? What experimental procedure are you going to do to try to support your hypothesis?

A. Make a lab book as previously described, Robbie, then put a nail in a container of each and see what you find! Do the experiment first and record your results. Although the "scientific method" usually includes doing some research before the experiment, that can be problematical for young students because they tend to look up the answer they are "supposed to get", and then fudge their observations, convincing themselves to discount their own experiment, and basically to practice what we call "junk science".

So I say, take a guess what the result will be, make that your hypothesis, then conduct the experiment and see whether the results support your hypothesis or tend to refute it :-)

Did you request assistance of the librarian before you decided there is not a lot of research? Your librarian will probably be happy to find an appropriate book for you. Good luck.

A. Rusting nails have been widely discussed on this website. May I suggest anyone following this thread for information should use the built-in search engine [top left corner of page] and FAQ's to get their answers. Alternatively, perhaps the students should do the experiments before going onto the Internet to get the answers, or is that too difficult and old fashioned!

A. I personally like the question regarding Dr Pepper on nails. I recently did a consulting report determining that discoloration of copper plated parts was due to the spilling of Dr Pepper into a tote of plated parts! Funny things do happen and no one guesses. But seriously, the idea of using the web for research for school science projects is for the student to locate the information that is available and decide which is pertinent. Asking a question and expecting the answer is just like asking your parents to do your homework!

A. Hello, Kristen. We get questions from first graders and from high school seniors, and they have to be answered differently depending on what grade you are in . . .

If you are in high school you should probably weigh the nail with an analytical balance before the experiment, and rub all the rust off after the experiment, and express the rusting in terms of weight loss. If you have the money and the interest, inexpensive electronic pocket scales are available if the school's balance isn't readily available.

If you are in a younger grade you can wipe the rust onto a coffee filter and pour the rusty water through the filter to capture the rest of the rust for a good visual indication of the amount of rust.

Good luck.

A. Numerous reasons. A few are: The bleach cleaned the surface. Bleach is sodium hypochlorite. This can break down into hypochlorous acid, free chlorine and ?. This will activate the nail surface as well as adding conductivity to the water.

A. I agree with Mr. Watts, Nathan, and would also add that bleach is a powerful oxidizing agent, (which is why it is a good disinfectant and color-remover). Since rust is iron oxide, it makes sense that a powerful oxidizing agent would help turn iron into iron oxide.

A. Mitch: I don't think "attract" is quite the right word in that context. Maybe you mean "cause"? Anyway, what did you see when you did the experiment? From that, maybe we can figure out what it taught you?

Ashley: It is predicted that within 3 years acid rain will be so bad that all nails will rust away; the shingles will blow off of all the houses; and no one will be able to sleep on rainy nights. Seriously, "acid rain" is a subtle effect which reportedly can have a serious impact on unbuffered high mountain lakes, but probably has little measurable effect on roofing nails.

If a little "rust forms on a nail" it has little effect. But think of where the rust came from (the strong steel plus oxygen was turned to powdery rust) and what will happen if something continues to rust indefinitely. Good luck.

A. For all you rusty nail people, perhaps if you search under corrosion on the internet you will find basic information on what you are looking for namely explaining your results; you have done the experiments haven't you ?

As a pointer, aqueous corrosion is an electrochemical process incorporating oxidation and reduction in the presence of an electrolyte. Areas on your nails become cathodic and anodic, the anodic areas "give" up electrons and the metal will slowly dissolve in this area. As your nail is essentially a short circuited cell, the cathodic areas are the site of the accompanying reduction reaction forming "rust".You can look up the chemical formulas in any basic chemistry textbook, though depending on your age I don't know whether your teachers want to you get into that or are just trying to get you to set up an experiment observe the results and write it up. Some of the things that can effect the reaction rate (corrosion rate) are electrolyte concentration (conductivity) and pH, temperature, oxidizing power.

Have any of you noticed what if anything happens to the sharp point on the nail during your experiment, that's a whole new can of worms for you to tussle with.

Happy homework,

A. Graham: this may not be a great experiment for 4th graders because the results you see are probably misleading. Coke is good at dissolving rust. My guess is the nail is corroding faster in the Coke than in spring water, but the Coke is dissolving the rust as fast as it forms. If you were in high school and doing this experiment, you could weigh the nail on an analytical balance before and after the test and measure the weight loss. Then your conclusion might be different. But just accurately record your observations in your lab book and you will have learned a lot.

Nicole: plain water contains dissolved oxygen that will combine with the iron in the nail to form iron oxide, also called rust, and a very small amount of heat. Almost all metals (except gold and a couple of other precious metals) will corrode in this fashion, combining with oxygen and forming an oxide of the metal in question. Actually, the corroded state is more stable (a lower energy state) than the metallic state--which is why you don't see most metals appear in metallic form in nature.

A. Rachel, the nail will not rust instantly. Nails wouldn't be very useful if they did, would they? So you need to allow perhaps a week for this experiment. But if you've been at it for several days with no rust, your nail is probably galvanized; you need plain steel or iron.

A. Tasha, this is not a subject that the industrial world is going to report on. We use nasty stuff for economical rust removal. Since this is probably an experiment, buy six cans of assorted sodas and experiment with it. What I fail to understand is how you will know that 6 rusted nails have the exact same amount of rust. It will very likely not remove all of the rust, so how are you going to tell which one removed the most? How do you know that the colas will not cause rust after a few days? Teachers that have experiments like this are only looking for the crudest evaluations or they should provide experimental design and equipment that is adequate for the analysis. Send me your teachers email address. I would like to get their side of this story.

"Challenging Environmental Mythology: Wrestling Zeus" on AbeBooks or Amazon (affil links) James: While 2nd-graders doing experiments with soda is okay, chemophobia is profound today, and proper reagents are gone from many high schools and even colleges, with students trying to do their "chemistry" course with ludicrous "reagents" like Dr. Pepper, flavored vinegars, and taco sauce. They can't get repeatable results, of course, but even if they could, what chemistry can possibly be learned from nonsense like whether Krispy Kreme Donut Glaze rusts a nail faster or slower than Ben & Jerry's Cherry Garcia Ice Cream? The waste of children's minds is terrible, but paranoia is a far more powerful force than concern about poor science education, so whatcha gonna do? My suggestion is that the kids try to learn what they can: experimental methodology like keeping a lab book, erasures absolutely forbidden, properly recording observations, forming testable hypotheses, and the difference between science and "junk science" :-) Ted Mooney, P.E. Striving to live Aloha finishing.com - Pine Beach, New Jersey 2003

A. The purpose of a research project is to find something out. If you already know the answer it is NOT research. I think you need to think a bit about the problem; you mention metal, copper and iron. Firstly, what do you mean by metal - it covers a multitude of sins. Secondly, what is rust (Clue - we generally call "rust" a brown material found on iron and steel. It contains a mixture of the metal oxide and hydroxide). Thirdly, what makes things rust? Once you have answered the last point, get some "metal", copper and iron and put them in conditions that will make them "rust".....Now THAT'S research.