Chemistry - Coordination Chemistry Question with Solution | TestHub

In the dichromate ion $[C{r}_2{O}_7{]}^{2-}$, each chromium atom is in the $+6$ oxidation state with a $3d^0$ electron configuration. The geometry around both central chromium atoms is tetrahedral. To achieve this geometry in high-oxidation-state oxo-complexes, chromium undergoes $s{d}^3$ hybridization. This involves one $4s$ orbital and three $3d$ orbitals ($d_{xy}$, $d_{yz}$, and $d_{xz}$) per metal atom. Since there are two chromium atoms, the total number of $d$-orbitals involved is $3\times 2=6$. Therefore, the correct option is (A).