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When H(2)O(2) is added to an acidified K...

When `H_(2)O_(2)` is added to an acidified `K_(2)Cr_(2)O_(7)` solution

A

a green colour solution is obtained

B

a yellow solution is obtained

C

a blue-violet solution is obtained

D

a green precipitate is formed

Text Solution

Verified by Experts

The correct Answer is:
C
On adding `H_(2)O_(2)` in acidic solution of `K_(2)Cr_(2)O_(7), H_(2)O_(2)` oxidise it to `CrO_(5)` (chromic penta oxide/chromic per oxide) and gives the blue-violet solution.
`K_(2)Cr_(2)O_(7) + H_(2)SO_(4) + 4H_(2)O rarr K_(2)SO_(4) + 2CrO_(5) + 5H_(2)O`

`CrO_(5)` on decomposition gives oxygen
`4CrO_(5) + 6H_(2)SO_(4) rarr Cr_(2) (SO_(4))_(3) + 6H_(2)O + 7O_(2)`
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