Oxidation numbers not considered per element

[kenhung123]

Why in some cases, you consider the oxidation number of an element seperately from the whole molecular formula? I don't know exactly but I think VO2SO4 and we were asked to find the oxidation number of vanadium. It doesn't work if you consider each element like S=-2 O=-2 but you must split it VO- and SO42- (consider only the VO-) to find oxidation number..

So should the first step in finding oxidation numbers be split up to ionic compound if it is?

[monokekie]

"VO- and SO42-" are linked by ionic bonding due to their electrostatic force of attraction

where as the single elements in those charged particles are covalently bonded to each other

That's probably why you need to separate the two charged particles first?

[bomb]

Exactly what monokekie said.

Each ionic compount has its own charge, it's oxidation number will be that charge. So split them up first