Sciencemadness Discussion Board

Experimenting with Euro coins

Aurus - 1-6-2010 at 09:29

I have done some experiments with Euro coins. Their composition is:
1c, 2c and 5c are made up of copper-plated iron,
10c, 20c, 50c are made up of an alloy called Nordic gold (89% copper, 5% aluminium, 5% zinc, 1% tin)
Finally, 1 Euro and 2 Euro coins are made up of cupronickel (75% copper 25% nickel) for the silver parts, and nickel brass (75% copper 20% zinc and 5% nickel) for the yellow parts.

Heating
Heating a 2 Euro coin with a propane torch seems to produce a black coating after the coin is removed from red heat. Presumably CuO.
With the 5 cent, the same. However, the 20 cent remains mostly the same colour, with some black at some points. Have you done any experiments with euro coins.

I've tried to dissolve 5 cent ones in hydrochloric acid but action is very slow due to the iron coating.

psychokinetic - 1-6-2010 at 12:53

Doesn't that carry a higher penalty than selling meth to a child, then abusing said child?

Shame really, this is interesting.

Aurus - 1-6-2010 at 13:33

I doubt that even if the authorities knew, I would be prosecuted for using something like 10 euros, due to the higher denominations of coins. That law is meant for large scale melting down. I am not sure if it actually exists in Europe. I know it exists in America, because the penny there is worth 1.7c in metal, with a face value of 1c.

Anyway, I didn't melt them, which was unfortunate, I expected the nordic gold or the cupronickel to melt. :( But I spent the blackened ones and it was ok.

turd - 1-6-2010 at 13:54

http://www.esta-cash.eu/en/newsletters/newsletter-no.-63.htm...
Quote:
Total destruction of banknotes and coins by individuals in small quantities should not be prohibited.

psychokinetic - 1-6-2010 at 15:16

Sorry, I didn't mean to derail the thread.

I'm now interested in my own country's coins. The compositions are interesting, and it is interesting to compare them to other countries.

Aurus - 2-6-2010 at 03:13

What are they?
I put 1 Euro and 5 cent coins in bleach and a black solid was created, creating a suspension. It would be interesting to investigate other reaction. Do you have any ideas?

bbartlog - 2-6-2010 at 06:56

Quote:
I've tried to dissolve 5 cent ones in hydrochloric acid but action is very slow due to the iron coating.


You mean the copper coating? Yes, HCl in the absence of air doesn't really do anything to copper. If you want to dissolve copper in HCl (or for that matter cupronickel) you need to oxidize the metal first; then the acid will react with the oxide. H2O2 and air both work for this.

psychokinetic - 2-6-2010 at 12:37

http://books.google.co.nz/books?id=rseuLmTlEZAC&printsec...

More than you ever wanted to know about coins. Values, compositions, history.