Tin forms the +2 and +4 oxidation states.
The empirical formula for tin oxide can be either SnO for tin (II) oxide or SnO₂ for tin (IV) oxide.
Oxygen forms almost exclusively the -2 oxidation state. Oxygen forms ions with a -2 charge when it reacts with metals.
To get instant result when calculating oxidation numbers of elements in the chemical compound, use this Oxidation Number Calculator. For better understanding on how to determine oxidation numbers, watch video below.
Rules for assigning oxidation numbers:
The oxidation number of a free element is always 0.
The oxidation number of a monatomic ion equals the charge of the ion.
Fluorine in compounds is always assigned an oxidation number of -1.
The alkali metals (group I) always have an oxidation number of +1.
The alkaline earth metals (group II) are always assigned an oxidation number of +2.
Oxygen almost always has an oxidation number of -2, except in H₂O₂ (when it is -1) and in OF₂ (when it is +2).
Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.
The algebraic sum of the oxidation numbers of elements in a compound is zero.
The algebraic sum of the oxidation states in an ion is equal to the charge on the ion.