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

May 27, 2017

Look at its anion companion's charge(s) and go from there.

#### Explanation:

You can determine the charge of a transition metal by looking at its anion (negatively charged ion) partner.

For example, lets say you are given $A u C l$, and you are asked to find the charge of $A u$, which would be the transition metal in this case.

You know that $A u C l$ is composed of a $C {l}^{-}$ anion and an $A {u}^{x}$ cation (positively charged ion), and that you want to find $x$. In this case, you know that the sum of the charges of $C {l}^{-}$ and $A {u}^{x}$ have to be $0$, since no charge is given for the compound ($A u C l$).

Therefore, we can set up an equation with the given information to find $x$.

Charge of transition metal + Charge of anion partner = Total charge of compound

$\left(x\right) + \left(- 1\right) = 0$

$x = 1$

Therefore, the charge of the transition metal for this example is $+ 1$.

You can use the given principle and bolded equation for pretty much any case where you are asked to find the charge of the transition metal. Just remember that if you have a compound like $C u C l 2$ that you write the total charge of the anion component of the substance. This would be $2$, since $\left(C {l}^{-}\right) \cdot 2 = - 2$ charge total for the anion component.

I hope that helps!