# What is the oxidation number of the metal in GaCl_2?

May 28, 2017

+2

#### Explanation:

Net Oxidation State of a molecule should be zero.

So,

$\left(G a\right) + 2 \left(C l\right) = 0$

In Chloride Ion Form, Cl has a charge of -1.

So Oxidation State of Chloride is -1.

Let The Oxidation State of Gallium be x.

So,

$\left[\left(x \cdot 1\right) + \left\{2 \cdot \left(- 1\right)\right\}\right] = 0$
$\Rightarrow x - 2 = 0$
$\Rightarrow x = 2$

May 28, 2017

This is clearly $\stackrel{I I +}{\text{Ga}} \ldots \ldots \ldots .$
Do this for $G a C {l}_{2}$, and we get $G {a}^{2 +} + 2 \times C {l}^{-}$. This is not a typical oxidation state for a Group 13 atom; it may be a mixed valence species of $G a C l$, and $G a C {l}_{3}$.