Q. Consider the following statements about manganate and permanganate ions. Identify the correct statements.

A. The geometry of both manganate and permanganate ions is tetrahedral.

B. The oxidation states of Mn in manganate and permanganate are +7 and +6, respectively.

C. Oxidation of Mn(II) salt by peroxodisulphate gives manganate ion as the final product.

D. Manganate ion is paramagnetic and permanganate ion is diamagnetic.

E. Acidified permanganate ion reduces oxalate, nitrite and iodide ions.

Choose the correct answer from the options given below :

Correct Answer: A and D Only

Solution

Both manganate (MnO₄²⁻) and permanganate (MnO₄⁻) ions have four equivalent Mn–O bonds and no lone pairs on the central atom.

Therefore, both ions have tetrahedral geometry, so statement A is correct.

The oxidation state of Mn in manganate is +6, while in permanganate it is +7. Hence, statement B is incorrect.

Oxidation of Mn(II) salt by peroxodisulphate ultimately forms permanganate ion, not manganate ion as the final product. Therefore, statement C is incorrect.

Manganate ion (Mn⁶⁺, d¹ configuration) contains one unpaired electron and is paramagnetic, whereas permanganate ion (Mn⁷⁺, d⁰ configuration) has no unpaired electrons and is diamagnetic.

Thus, statement D is correct.

Acidified permanganate ion acts as a strong oxidizing agent, not a reducing agent, so statement E is incorrect.

Hence, the correct statements are A and D only.

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