 In this video we will look at the chemistry behind the production of iron from iron ore. This is the reactivity series of metals which was discussed in this video. In early earth history iron like all other metals would have been found as an element in the crust of the planet. Later when plants evolved that released oxygen iron combined with this new reactive gas making oxides. This process would have taken many millions of years. Iron is found as the compound iron oxide in the ore known as hematite. To displace iron from its oxide we need a material that is more reactive than iron inexpensive and easily obtainable carbon ticks all of those boxes. Until the industrial revolution in the 18th century the source of carbon had been charcoal which contributed to deforestation in many parts of Europe. The discovery that coke almost pure carbon could be made from coal was a major breakthrough. Carbon acts both as a reducing agent it can remove oxygen from a compound and as a fuel to supply the high temperatures a furnace needs over 1500 degrees centigrade to enable the reaction to proceed. The actual reaction is a three step process. The carbon burns to produce carbon dioxide. The carbon dioxide reacts with more of the carbon to make carbon monoxide. The carbon monoxide then reduces the iron oxide to iron. The reduction reaction can be summarized as this. This reaction can be classified in several ways. This is a displacement reaction as carbon is more reactive than iron and so can displace iron from iron oxide. The reaction is also an example of a reduction reaction where oxygen is removed from a compound. At the same time carbon is being oxidized to make carbon dioxide iron oxide has been reduced to iron. As reductions and oxidation occur simultaneously these are called redox reactions. The transfer of electrons which is what chemistry is all about can be tracked during this redox reaction which gives another more useful definition of what redox means. We look at how the oxidation states of iron and carbon change in the reaction. Iron begins in the positive three state and ends up in the zero state. Remember all elements have a zero oxidation state. To achieve this the iron three positive ion must gain three electrons. Reduction is gain of electrons. Carbon begins in the zero oxidation state and ends up in the positive four state. Carbon must have lost four electrons to achieve this change. Oxidation is loss of electrons. All of the electrons lost by the carbon atoms are given to the iron three positive ions so we have reduction and oxidation a redox reaction. To recall which way electrons move in a redox reaction think of oil rig. Oxidation is loss of electrons. Reduction is gain of electrons. Only metals below carbon in the reactivity series can be obtained by reduction of their oxide using carbon. Copper is extracted under less harsh conditions when compared to iron as it's a less reactive metal. This in part explains why copper extraction was discovered well before that of iron. If you liked the video give it a thumbs up and don't forget to subscribe comment below if you have any questions why not check out our Fusco app as well until next time