Oxygen almost always has an oxidation number of -2. Therefore in the formula for the mineral wüstite, #FeO#, what must the oxidation number for iron be? In the formula for hematite, #Fe_2O_3#, what must the oxidation number for iron be?

1 Answer
May 13, 2017

Answer:

Actually oxygen usually has an oxidation number of #0#; certainly the dioxygen you and I breathe right now has this oxidation number.

Explanation:

In its oxides, an oxidation number of #-II# is typical. And since, for neutral compounds, the sum of the oxidation numbers is #0#. For #"ferrous oxide"# we have #Fe^(+II)O^(-II)#; and for #"ferric oxide"#, #Fe_2^(+III)O_3^(-II)#,

The #"ic/ous"# ending generally specifies the higher oxidation state versus the lower. As an example stannous chloride, and titanous chloride are #SnCl_2# and #TiCl_2# respectively. Stannic chloride, and titanic chloride have the formulae, #SnCl_4#, and #TiCl_4#, and are distillable liquids.