Why is Sulfur Dioxide called Sulfur(IV) Oxide?

Question

I get the SO-subscript 2 part easy enough, but where does the (IV) in the title come from? What does it imply and why is it there?

Answer 1

Its because sulfur is in the +4 oxidation state. I don't know why they put it there unless there is another form of sulfur dioxide where sulfur is in a different oxidation state.

Answer 2

Sulfur can be II,IV and VI
sulfur in the oxidation state +4 has a valency of 4 and oxygen has a valency of 2.hence in order to make sulfur stable,2 atoms of oxygen will combine with the Sulfur.

Answer 3

The (IV) is indicating that the sulfur atom has a valence charge of +4. Indicating that it has four electrons to share in bonding. Each of the oxygen atoms have a -2 valence charge. Indicating that they can each accept two electrons when bonding. The net result must be zero for a molecule to be stable.

Answer 4

There are two oxides of sulphur, SO2 and SO3.
You could call them sulphur dioxide and sulphur trioxide, but you could also call them sulphur(IV) oxide and sulphur(VI) oxide. The Roman numeral is the oxidation state, or apparent charge on the S atom.