Free Range Chemistry 10 - Copper from Malachite

now I have um some beautiful little malachite carvings here some um animals we have uh there's a a dog um there's well a dog's head actually the rest of him sort of had an accident uh we have a frog a lion a little bird and a cat um so we're going to do a little experiment on one of these to see if we can get the copper out of the malachite here good I can relax now right well let's take let's take the dog's head mainly CU my mom quite liked the other ones and she wanted one of those but anyway so let's take um chip here and we're going to heat him up now take chip and at the moment he's this lovely green color but if I heat him up in the in the bunson here the copper carbonate that he's made of is going to decompose and it gives out uh carbon dioxide gas and forms copper oxide and the copper oxide we'll know when we're beginning to get some copper oxide because the copper oxide is black okay so actually already you can see that the bottom of the malachite here we're getting a black coloration and this is as the carbonate is decomposing and forming copper oxide we can look at the equation for this so here we have the equation copper carbonate plus heat forms copper oxide and carbon dioxide gas gas right well I'm going to heat him up a little bit more strongly um over here on a piece of charcoal remember the charcoal is um impure carbon right so let's just heat him up strongly so he's decomposing and forming oops there goes a bit of him forming copper oxide so he's certainly very black now but the copper oxide is going to well begins to react with the um carbon in the charcoal and the carbon steals away the oxygen from the copper oxide forming carbon dioxide leaving behind the copper and this is the well essentially the process that's used to make many metals you heat up the metals with some car carbon and the carbon steals away the oxygen from the ores leaving the metal behind I think I'm doing quite nicely we beginning to get some molten copper forming all right let's see if I can pick up this with the tongs okay thank you and put this into some water here just to cool it down and if I pick out the lump that we've just made here actually there's a nice bit in here I can see y you can see the reddish color here of well the copper metal Okay so we've actually converted well first of all the copper carbonate the natural mineral the malachite into copper oxide by driving out the carbon dioxide leaving copper oxide the black color and then the uh oxygen has been stolen away from that using the charcoal here from the the carbon stealing away the oxygen to reveal the copper and these are some lumps that we made in the earlier lectures so copper metal of course copper was the first metal that was chemically prepared after the Stone Age when people using stone tools flints as axes and spearheads and so on after that um we came the Bronze Age or the C coer age and this was because copper was one of the easiest elements to actually obtain it's much easier to make than iron so after the Bronze Age came the Iron Age when they had higher temperatures available to make ion from ion oxide but here we're making some copper here is the reaction there for the copper oxide having its oxygen taken away by the carbon to form carbon dioxide but leaving the copper behind now

Channel: Royal Society Of Chemistry

Views: 35,972

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Id: 8ocYcA_xi98

Length: 4min 25sec (265 seconds)

Published: Fri May 17 2013