Question

How do you find the oxidation number of complex ions?

Answer 1

The oxidation number of a complex ion or a complex compound is the charge carried by that specific ion in terms of integers.
It results because of the presence of extra electrons, which corresponds to negative oxidation state, or the absence of electrons, which corresponds to the positive oxidation state.

Complete step-by-step answer: The term oxidation number could be defined as the number which provides us the information whether the given species is anionic or cationic in nature. It is a crucial factor of any given species because it also tells us about the nature or the reactive properties of that species. For instance, if a species is possessing a negative oxidation number or state, it tells us that the species is capable of binding with the species which have positive oxidation number or state. Moreover, species which have negative oxidation numbers can also donate their electrons because of the higher abundance of electron clouds, and so they are also termed as bases, whereas in the case of the positive ions, they can be termed as acids, as they have electron attracting properties.
Let us consider an example, in order to understand this more clearly. Consider the species ${{[Ag{{(CN)}_{2}}]}^{-}}$. The oxidation number of the coordination sphere is $-1$. This is because the individual oxidation numbers of the components involved in the coordination compound is $+1$ and $-1$ for silver and cyanide ions respectively.

Note: The oxidation number of a compound is the total charge which is possessed by a molecule or an ion or a component of a coordination sphere.
It is generated solely because of the gain of one or more than one electron or loss of it.