Extraction of metals

Most metals are found on the earth as compounds which are called ores

An example is haematite - this contains iron

There can be many ores for each metal

Metals like gold, silver and platinum are very unreactive, these will be found in their native states (as elements).

An ore is a substance such as haematite (contains iron) which contains enough of a metal to make a profit from extraction.

I.e. It costs less to extract it that what you can sell it for.

In these slides we have mentioned the metal is reduced, this means the carbon is oxidised.

You can think about it like this:

The carbon is oxidised (gains oxygen)

The metal is reduced (loses oxygen)

Using your knowledge of the reactivity series you are to predict are going to predict which of these metals you can extract by heating (reducing) with carbonand explain why.

Watch the following video for copper first and apply this to magnesium oxide and lead oxide 

https://www.youtube.com/watch?v=wNqiCjR2ics

Record any observations you would expect to make - in the table on the following slide - copper will be done for you

Example -

Copper oxide (II)

Copper would be reduced in this reaction because it is less reactive than carbon, observations I would see are small chunks and flakes of copper in the crucible after heating and the carbon would have escaped as carbon dioxide gas. The carbon will displace the less reactive copper from the oxygen to form carbon dioxide.

Tungsten is another metal that is reduced from its ore, however hydrogen is used instead of carbon even though carbon would be cheaper.

This is because carbon forms a compound with the tungsten during this process (tungsten carbide), where as the hydrogen forms water with the oxygen and the tungsten extracted using hydrogen is very pure

The word equation is :

Tungsten oxide(s) + hydrogen(g) --> tungsten(s) + water (g)(as steam).