1So that means first deep blue solution is formed and then the compound CrO5 decomposes to give Cr3+ which is green in colour?
What actually happens when we add Hydrogen Peroxide to acidified Potassium Dichromate? Do we get a deep blue solution or a green solution? I have read both of them.
Will the result be different if Sodium Peroxide is added instead of Hydrogen Peroxide?
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11When hydrogen peroxide is added to a acidified solution of dichromate (or any other Cr (+VI) species) , a very complicated reaction occurs. The products depends on the pH and the concentration of Cr.
Cr2O72- + 2H+ + 4H2O2→2CrO(O2)2 + 5H2O
A deep blue violet coloured peroxo compound is formed. This decomposes rapidly in aq solution into Cr3+ and dioxygen.
In less acidic solutions of potassium dichromate an hydrogen peroxide give salts which are violet colored and diamagnetic. These are thought to contain [Cr(O2)OH-], but the structure is nt known as the compounds are explosive.
In alkaline solution with 30% hydrogen peroxide, a red-brown compound K2Cr3O8 is formed which is a tetraperoxo species [Cr(O2)4]- and contains Cr(+V).
In ammonia solution the dark red brown compound (NH3)3CrO4 is formed which contains Cr(+IV)
Aadesh Madnaik Nice answer! Thanks a lot.Upvote·0· Reply ·2017-09-10 15:45:02
11@Euclid
It gives blue solution only in ethereal solutions. In concentrated, it gives green colour
1ya.....potassium dichromate in acidic medium gives Cr+3 but not in presence of H2O2...
in less acidic solution K2Cr2O7 and H2O2 give salts that are violet coloured and diamagnetic due to formation of [CrO(O2)(OH)] -
11@ Swordfish what you din understood, sabkuchh toh likha hai in the previous post