confused... (1 Viewer)

[Mr Chi]

how do you write a compound when it is something like iron (III) oxide. Does the (III) mean number of oxygen atoms in this case? , and is this the same for all compounds like this? Does this have any relation to oxidation numbers?

 

[Templar]

It's the oxidation number. Fe2O3

 

[insert-username]

The III, like Templar said, refers to the valency or oxidation number of the metal. Roman numerals only appear for compounds that contain transition elements with multiple valencies. Hence, lead (II) chloride is PbCl₂, and lead (IV) oxide is PbO₂


I_F

 

[Mr Chi]

The III, like Templar said, refers to the valency or oxidation number of the metal. Roman numerals only appear for compounds that contain transition elements with multiple valencies. Hence, lead (II) chloride is PbCl₂, and lead (IV) oxide is PbO₂


I_F

with the lead (IV) oxide, can it also be Pb2O4 ?

 

[sikeveo]

Why write it like that?

 

[xvelidras]

with the lead (IV) oxide, can it also be Pb2O4 ?

Technically, since Pb(IV) oxide is ionic, yes it is the same thing. But by convention, the formula of ionic compounds such as Pb(IV) oxide is empirical, giving the relative numbers of ions of each type in the compound, in the lowest common ratio

 

[Riviet]

Just adding on, the emperical formula is the lowest whole number ratio of elements in the compound.