Extracting Metals from Rocks L.O: To understand what the reactivity series is, and what reduction and electrolysis are. Saturday, 10 November 2018

Starter CARBON SODIUM NITROGEN ZINC OXYGEN METALS NON-METALS Starter MAGNESIUM CARBON SODIUM NITROGEN ZINC OXYGEN Sort the elements into 2 columns – metals and non-metals… CALCIUM NEON ZINC SODIUM NEON POTASSIUM ARGON MAGNESIUM NITROGEN HELIUM TIN TIN HELIUM ALUMINIUM CARBON OXYGEN IRON CHLORINE ARGON ALUMINIUM KRYPTON CALCIUM POTASSIUM IRON COPPER COPPER KRYPTON CHLORINE

The reactivity series The reactivity series is a list of metals that are arranged in order of how reactive they are. The most reactive metals are at the top The least reactive are at the bottom. The position of each metal in the reactivity series is important. Whether a metal is higher or lower than carbon (the only non-metal in the series) determines the method that is used to extract it from its ore.

… and it can be extracted from it’s oxide by reduction using carbon… Metal Reactivity Symbol Potassium K Sodium Na Calcium Ca Magnesium Mg Aluminium Al Carbon C Zinc Zn Iron Fe Tin Sn Lead Pb The reactivity series Here it is: … and it can be extracted from it’s oxide by reduction using carbon… What do you notice about one of the metals? … and can be extracted from it’s oxide using electrolysis Carbon Anything below carbon is less reactive than it… C Anything above carbon is more reactive than it… We just include it for comparison… Carbon – it’s not a metal at all!

Reduction using carbon A metal below carbon in the reactivity series can be extracted from its ore by reacting it with carbon. The reaction that takes place is called a reduction reaction, which is where oxygen is removed from the metal ore. O O

For example… Iron oxide (the ore of iron) is reduced in a blast furnace to make iron. Iron is less reactive than carbon so when iron oxide and carbon react the oxygen is removed from the iron ore, leaving iron metal. O C O Fe C Fe Fe Fe Fe

Electrolysis Metals that are more reactive than carbon, such as aluminium, can't be extracted using carbon. So different processes, such as electrolysis have to be used. These processes are much more expensive than reduction with carbon because they have many stages and use a lot of energy.

For example… Electrolysis can be used to extract aluminium from its oxide ore. A high temperature is needed to melt the aluminium oxide so that the aluminium can be extracted This takes lots of energy, making it an expensive process.

Questions Name the method used to extract a metal if it is... ...above carbon in the reactivity series. ...below carbon in the reactivity series. Is an element at the top of the reactivity series more or less reactive than the elements below it? When a metal ore is reduced by carbon, what is removed from it? Why are other processes of extraction more expensive to carry out than reduction with carbon? Give two examples of metals that are extracted using electrolysis.

Questions – Application What process is required to extract each of these metals from their metal oxides? Use the reactivity series to help you. Tin Calcium Zinc Potassium

Answers – Fact Recall Method: More reactive Oxygen Electrolysis Reduction More reactive Oxygen They have many stages and use a lot of energy Any two from: e.g. aluminium, magnesium, calcium, sodium, potassium.

Answers - Application Reduction with carbon Electrolysis