Block D and F Elements

K₂Cr₂O₇ + H₂O₂ + H₂SO₄->  + K₂SO₄ + H₂O compound 'X' is ->CrO₅

Oxidation state of chromium = +6.

Potassium permanganate in alkaline medium oxidise lodide to lodate.

$2Mn{O}_4^{-}+H_{2}O+I^{\Theta }\stackrel{}{\to }2Mn{O}_2+2O{H}^{\Theta }+I{O}_3^{\Theta }(A)$            

Compound A is  . Therefore, oxidation state of 1is + 5.

KMnO₄ decomposes upon heating at 513 K and forms K₂MnO₄ and MnO₂.

2KMnO₄  K₂MnO₄ + O₂ + MnO₂

The colour changes due to change in pH not due to its reaction with water.

Each of the element in group III  to VIIIB  can show the maximum oxidation state equal to its group number.

Mn is in group seven shows a maximum oxidation state of +7 in KMnO₄

Zn²⁺ has no unpaired electron and colourless in aqueous solution.

This is an example of chromyl chloride test

K₂Cr₂O₇ + 4KCl + 6H₂SO₄? 6KHSO₄ + 2CrO₂Cl₂ + 3H₂O

Oxidation state of Cr is +6.

A, B and C are correct.

Mn₂O₇ is a green oil at room temperature.

V₂O₄ react with acids to give VO²⁺.

CrO is Basic and CrO₃ is acidic.

V₂O₅ react with acids as well as alkali.