Oxidation state trends in group 4

OXIDATION STATE TRENDS IN GROUP 4 This page explores the oxidation states (oxidation numbers) shown by the Group 4 elements - carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb). It looks at the increasing tendency of the elements to form compounds in which their oxidation states are +2, particularly with reference to tin and lead.
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Some examples of the trends in oxidation states The overall trend The typical oxidation state shown by elements in Group 4 is +4, found in compounds like CCl4, SiCl4 and SnO2.
	Warning: Don't fall into the trap of quoting CH4 as an example of carbon with a typical oxidation state of +4. Because carbon is more electronegative than hydrogen, its oxidation state in this instance is -4!
However, as you go down the Group, there are more and more examples where the oxidation state is +2, such as SnCl2, PbO, and Pb^2+. With tin, the +4 state is still more stable than the +2, but by the time you get to lead, the +2 state is the more stable - and dominates the chemistry of lead. An example from carbon chemistry The only common example of the +2 oxidation state in carbon chemistry occurs in carbon monoxide, CO. Carbon monoxide is a strong reducing agent because it is easily oxidised to carbon dioxide - where the oxidation state is the more thermodynamically stable +4. For example, carbon monoxide reduces many hot metal oxides to the metal - a reaction which is used, for example, in the extraction of iron in a blast furnace.