But let's see, It's a reaction of copper chloride with a cupcake holder, which is in fact, just aluminium.

First of all, I'm going to dissolve some up and make a fairly concentrated solution, so but it makes rather nice green solution.

In fact, perhaps we'll make the solution up in here.

It's easier to stir.

You can see it's a long time since I've done such things.

So we're making up the concentrated solution of copper chloride.

It's now mostly dissolved, and it's a really very pretty color.

I'm going to place this here on DDE.

So imagine I'm doing this on the floor of our living room, which has a carpet on it.

And the cupcake holder was on the carpet, so I pulled this in on DDE.

As you can see here, nothing much happens to begin with.

But then, if you want, it starts boiling really quite nicely.

You can see the nice precipitate of copper.

Well, we can take it out and you can see there now Imagine I was doing this for my Children, who were quite small at that time on DDE Bush.

The stuff went through the cupcake holder and onto the carpet and through the carpets, and my wife was not at all pleased because they're in the middle of our carpet was a whole.

We now have a new carpet, so the first time it went through quite quickly.

So this time I got to do a double.

We have two aluminium cupcake holders here on the strong solution of copper chloride, and we pour it in here.

Now watch, see if anything happens.

The reaction's a bit slow to start because the aluminium has an oxide layer, but now it's got going and you can see it's begun.

Boiling got really quite excited on DDE.

It's now gone through both layers, and you can see there's rather nice color of the copper.

The metallic copper on what has happened is the aluminium has reacted with the copper to make aluminium chloride on copper metal.

It feels really quite warm even through here, so the chemistry is that the aluminium is reacting with the copper chloride to make metallic copper, which is what you can see.

They're andan aluminium salt.

Now the message of this is that even something like copper chloride, which sounds a fairly innocuous material, can be pretty reactive if you put it in the presence of the right material in this case, aluminium.

So Kim.

It should always be careful when designing a reaction and the container to make sure that they don't get an unexpected reaction.

And if I had thought about that, we would have saved money for a whole carpet.