Chemistry Of Mn And Cr Compounds

Considering the following reaction,
3 MnO ₄^2– + 2 H ₂ O ⇌ 2 MnO ₄^– + MnO ₂ + 4 OH^–
The reagent that facilitates the removal of OH^– ions to ensure the completion of the conversion of K₂MnO₄ to KMnO₄ is:

1. KOH
2. CO₂
3. SO₂
4. HCl

The manganate and permanganate ions are tetrahedral, due to:

1.	The \pi -bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese.
2.	The \pi -bonding involves the overlap of p-orbitals of oxygen with d-orbitals of manganese.
3.	Absence of \pi -bonding.
4.	The \pi -bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese.