Question

When given a chemical formula, how can you determine the charge on a transition metal?

Answer 1

Hint: Chemical formula of any molecule represents the number and types of atoms present in that molecule. In this atom are described by the elemental symbols and the number of atoms are described by the subscript followed by the elemental symbol.

Complete answer:
We can determine the charge of any transition metal by looking at its anion substance and anion are those substances which form negatively charged ions.
This can be explained by taking the example of $AuCl$where we know that this compound is composed of copper and chloride ions where $A{{u}^{x+}}$is cation in i.e. positively charged species whereas $C{{l}^{-}}$ is anionic in nature. Now we have to find out the value of x in this case. We know that sum of the charges of $A{{u}^{x+}}$and $C{{l}^{-}}$ is zero which describes that no charge is given for the compound $AuCl$.
The equation followed to find x is as given below:
Charge of transition metal + charge of anion = total charge of compound
We know that chloride ions i.e. $C{{l}^{-}}$ acquire negative charge of 1 i.e. -1
$\therefore x-1=0$, which defines x =1 i.e. the charge of transition metal in this compound is one.
Hence in this way we can calculate the charge of transition metal by knowing its chemical formula.

Note: Transitions metals are those elements which have partially filled d subshell or which form cations with an incomplete d subshell. In periodic table groups 3-12 are referred to as transition elements groups i.e. d-block elements.