The incorrect statement is :


The incorrect statement is :


  1. In manganate and permanganate ions, the $\pi$-bonding takes place by overlap of p-orbitals of oxygen and d-orbitals of manganese

  2. Manganate ion is green in colour and permanganate ion in purple in colour

  3. Manganate and permanganate ions are paramagnetic

  4. Manganate and permanganate ions are tetrahedral

Correct Option: 3,


Option 1) Manganate $\Rightarrow \mathrm{MnO}_{4}^{2-}$,

Permanganate $\Rightarrow \mathrm{MnO}_{4}^{-}$

After excitation

$2 \times 2 \mathrm{p}_{\pi}-3 \mathrm{~d}_{\pi \sigma}$

$2 \times 2 \mathrm{P}_{\pi}-3 \mathrm{~d}_{\pi}$

$1 \times 2 \mathrm{P}_{\pi}-4 \mathrm{P}_{\pi}$

(2) $\mathrm{MnO}_{4}^{2-} \Rightarrow$ green

$\mathrm{MnO}_{4}^{-} \Rightarrow$ purple/violet

(3) Manganate contains 1 unpaired electron hence it is paramagnetic

where as permanganetic contains no unpaired electrons hence it is diamagnetic.

(4) Both have $\mathrm{d}^{3} \mathrm{~s}$ hybridisation hence both have tetrahedral geometry.


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