Which beverage cleans pennies best?

Hi Alexia. Cleaning pennies with beverages is fine if focused on showing young children how to make a "lab book", how to distinguish hypotheses from observations, the steps involved in "the scientific method", etc., without exposing them to any dangerous chemicals or situations.

The "lameness" is that there is no "extensible" lesson. It's like being taught that 429 + 252 = 681. Yes, that answer is correct, but only the method of arithmetic is valuable, not that one individual fact. Learning that strawberry lollapalooza cleans pennies better or worse than pineapple-grape punch is worthless knowledge, but it's probably hard to convince kids that practicing the method is far more important than the particular result they got :-)

Luck & Regards,

A. Whether 14 drinks is overwhelming or not is a question of how much money you have to spend on them, Caitlin, and how much room you need to maintain your experiment. But it would be far better to have 3 beaker [beakers on eBay or Amazon]s each of 4 beverages than one beaker each of 14 beverages because one test can be too subject to some small corruption to be trustworthy.

You could try those 14 beverages, or you could expand it to thousands, but what would be the POINT of trying to categorize every beverage by its ability to clean pennies? It would be ridiculous. What would you learn from the fact that cherry pop is better or worse than strawberry (they are probably both secret artificial flavors that have nothing to do with the real fruits anyway).

So maybe pick four that are very different from each other like lemon juice, coffee, water, and whole milk. The POINT is to learn about forming a hypothesis, making a "lab book", experimental procedures, and the scientific method -- not to actually learn which flavor of soda you should clean pennies with. Good luck!

A. Lemon Juice. Just leave the pennies in over night and clean they'll be.

A. Caitlin,

Us old ones are only renting the planet so we can pass it on to youngsters like yourself. Whilst we are always willing to help you learn, it would be stupid just to hand everything on to you; what will you do when we are long gone and you are in charge? You must learn by experimentation so that you, in your turn, will be able to hand on your knowledge to the next generation. As Ted says, do the experiment and then, if you don't understand something, ask. You will learn one heck of a lot more by doing it yourself than just taking the soft option and being told the answers.

Good luck and enjoy science - it is a lot of fun.

A. I've also experimented with this, and have found that coke works the best.

A. Without knowing what grade you are in, Karen, I don't know if it would help you to know that pH is the "negative log of the hydrogen ion concentration". But what it means in simpler terms is that acidity and low pH are the same thing. A pH of 0 is fully acid as you can get; a pH of 7 is neutral, and a pH of 14 is as fully alkaline.

This question of cleaning pennies has been asked and answered on this site over a hundred times, so you will have no trouble filling 3 pages if you do a search.

But I disagree that the most acidic beverage is necessarily the best penny cleaner. I think that there are teachers, administrators, and textbook publishers who should get Fs, because few have a clear understanding of this experiment they are asking millions of students to do. Add a pinch of salt to virtually any juice and it will clean much better than a more acidic juice. Please don't just believe me, get some pH paper and a dash of salt and try it!

Hi, Candance. It's probably time for you to run an experiment and find out if you're right. Science is about determining how things actually are as opposed to how we'd like them to be :-)

Take a really quick lesson from one of the world's greatest physicists and teachers, Richard Feynmann (dec.)

A. Most of the non-exotic metal cleaners are going to be an acid of some form.
Common ones that you have seen in previous posts are acidic to some level.
Most fruit juices - the more tart, the more acid.
Soda pop-some fruit acids, some phosphoric acid and short term carbonic acid from the CO2 (turns to carbonates a non acid)
Coffee is not normally considered an acid, so would work poorly.
Milk contains lactic acid, but it also contains a lot of calcium, so would be nearly neutral. Buttermilk might be a tiny bit more acid.
If you distill ants, you will get some formic acid, which is extremely hard on the human body (ant bites).

Your project should not be just what cleans pennies best, but why it does. You can find pH values for most things on line. Low is more acid.

A. Although it's always nice to have satisfying results, in a school science project the teachers are more looking at whether you put a decent amount of work into things and whether you used correct procedures. In science, discovering that nothing works is still a result you can learn from. In industrial R&D, discovering that nothing works means you can't create a product to sell and you have nothing to show for your time and effort.

A. The important thing about any project is to understand what has happened. There is nothing wrong with repeating work that someone else has done and getting the same result - it shows that you and whoever else has done the work have either all be very good practitioners or everyone has made the same mistake!
I strongly recommend watching what happens in any experiment and then try to put your observations in scientific terms. We all know that some drinks can clean pennies and make them bright, but the question is why... You may want to consider which drinks clean pennies fastest and what other factors (temperature, agitation, age and/or concentration of drink etc) affect the rate of cleaning. When you can answer these bits, you can start to consider yourself a scientist, but to do that, you need to observe what is happening. In my opinion, the fun thing about science is the actual doing of it.
I am also of the view that there is no such thing as a negative result in science; it may not be the observation you wanted to see, but it is still a bit of information you didn't have before you did the experiment.
As you do more science, you see many more things and gain more knowledge, until one day, you have so much knowledge about something that you can consider yourself an expert on that topic.
Good luck and enjoy your science. Do not worry about repeating other people's work, buy try to understand what you have done and why you have seen what you have seen.

A. Hey, I think Taco Bell sauce is best do it!! ;)