Question

The manganate and permanganate ions are tetrahedral due to:

• A. The pi-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese
• B. There is no pi -bonding
• C. The pi-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese
• D. The pi-bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese

Answer 1

The correct option is A

The pi-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese

Explanation for the correct option:

Option A:

1. The manganate ion is a negatively charged ion. Its molecular formula is ${{\mathrm{MnO}}_4}^{2-}$
2. In the manganate ion, two oxygen atoms form a double bond with the manganese atom while the other two atoms only form a single bond.
3. The electronic configuration of oxygen is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$ and that of manganese is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^5$
4. In this ion pi bonds belong to the p-orbitals of oxygen and manganese's d-orbitals ($\mathrm{d\pi }-\mathrm{p\pi }$)
5. The permanganate ion is also a negatively charged ion. The chemical formula for permanganate is ${{\mathrm{MnO}}_4}^{-}$
6. Three oxygen atoms have double bonds with manganese atoms in this permanganate ion, while one oxygen atom only has a single link
7. The pi bonds belong to the p-orbitals of oxygen and the manganese d-orbitals ($\mathrm{d\pi }-\mathrm{p\pi }$).

Explanation for the incorrect options:

Option B: There is no pi-bonding

1. There is pi bonding in manganate and permanganate ion between pi-orbital of oxygen and manganese d-orbital.
2. Hence, it is an incorrect option.

Option C: The pi-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese

1. The electronic configuration of oxygen is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$ and that of manganese is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^5$
2. The pi bonds belong to the p-orbitals of oxygen and the manganese d-orbitals.
3. Hence, it is an incorrect option.

Option D: The pi-bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese

1. The electronic configuration of oxygen is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$ and that of manganese is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^{2}3{\mathrm{d}}^5$
2. The pi bonds belong to the p-orbitals of oxygen and the manganese d-orbitals.
3. Hence, it is an incorrect

Hence, The manganate and permanganate ions are tetrahedral because of the bonding involving the overlap of the p-orbitals of oxygen with the d-orbitals of manganese.