Question

Oxidation state of $Cr$ in ${K_3}[Cr{({C_2}{O_4})_3}]$ is?

Answer 1

Oxidation state indicates the degree of oxidation for an atom in a chemical compound. It is the imaginary charge that an atom would have if all the bonds to atoms of different elements were completely ionic. Oxidation states are typically represented by integers, which can be positive, negative, or zero.

Complete step by step answer:
Chromium is the fourth transition metal found on the periodic table, and has an electron configuration of $\left[ {Ar} \right]{\text{ }}3{d^5}\;4{s^1}$ . It is also the first element in the periodic table whose ground-state electron configuration violates the Aufbau principle. This occurs again later in the periodic table with other elements and their electron configurations, such as copper, niobium, and molybdenum. This occurs because electrons in the same orbital repel each other due to their like charges. In order to determine the oxidation state of the chromium atom in the ${K_3}[Cr{({C_2}{O_4})_3}]$ complex, we need to balance the oxidation states of other groups in the complex such that the whole complex remains neutral as there is no charge over the complex.
Let the oxidation state of the chromium atom be $x$ .
The oxidation state of potassium atom, $K = + 1$
The oxidation state of oxalate ion, ${C_2}O_4^{2 - } = - 2$
Let us determine the oxidation state of the chromium central atom
$\Rightarrow + 3 + x + 3( - 2) = 0$
$\Rightarrow x = + 3$
Thus, the oxidation state of $Cr$ in ${K_3}[Cr{({C_2}{O_4})_3}]$ is $+ 3$ .

Note: Chromium is a chemical element with the symbol $Cr$ and atomic number $24$ . It is the first element in group VI. It is a steely-grey, lustrous, hard and brittle transition metal. Chromium is the main additive in stainless steel, to which it adds anti-corrosive properties. Chromium is also highly valued as a metal that is able to be highly polished while resisting tarnishing.