This is a fantastic experiment. I have used it to reinforce a variety of different topics;

My Year 10’s see this while we investigate different ways of extracting metals. I usually talk about high-grade ores and the fact that pre- 1980’s coins were made out of actual copper. As the cost of copper increased the coins became worth more than their face value. Many people started to melt them down to sell. To get around this the Royal Mint started making them out of Nickel with a thin layer of copper on top. When we add them to conc. acid the pre- 1980 coin has it’s layers of copper removed layer by layer at the same time, leaving a very thin coin (about 0.001 meters thick) with the queen still clearly visable. The post- 1980 coin has the layer of copper removed leaving the nickel coin inside. Not that anyone would, but I would imagine the silver coloured coin could possibly be passed of as a 10p coin when you use the bus!!!

My Year 12’s and 13 see this experiment during metal complex chemistry.

If you have any other ideas or comments regarding this reaction please email me and I will add them here.

Preparation Time                5 Mins

Difficulty                            4/10

WOW! Factor                    5/10

LINK TO RECIPE

Ultra Thin Coin