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JEE Main202431 Jan 2024Morning ShiftChemistryd and f Block ElementsActual

Identify correct statements from below: A. The chromate ion is square planar. B. Dichromates are generally prepared from chromates. C. The green manganate ion is diamagnetic. D. Dark green coloured K 2 MnO 4 disproportionates in a neutral or acidic medium to give permanganate. E. With increasing oxidation number of transition metal, ionic character of the oxides decreases. Choose the correct answer from the options g

Options

  1. AB, C, D only
  2. BA, D, E only
  3. CA, B, C only
  4. DB, D, E only

Correct answer

D. B, D, E only

Step-by-step solution

A. CrO 4 2 - : the geometry of chromate ions is tetrahedral. B. 2 Na 2 CrO 4 + 2 H + → Na 2 Cr 2 O 7 + 2 Na + + H 2 O Dichromates are usually prepared from chromates and this is obtained by the combination of chromite ore with sodium/potassium carbonate in the presence of air. C. Green manganate is paramagnetic with 1 unpaired electron. D. Disproportionation reaction of managanate in acidic or neutral medium is one of the preparation method for the permanaganate. 3 MnO 4 2 - + 4 H + → 2 MnO 4 - + MnO 2 + 2 H 2 O Da

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