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The colour of K(2)Cr(2)O(7) changes from...

The colour of `K_(2)Cr_(2)O_(7)` changes from red-orange to lemon-yellow on treatment with `KOH_((aq.))`, because of:

A

The reduction of `Cr^(VI)` to `Cr^(III)`

B

The formation of chromium hydroxided

C

The conversion of dichromate to chromate

D

The oxidation of potassium hydroxide to potassium peroxide

Text Solution

Verified by Experts

The correct Answer is:
C
The conversion of dichromate to chromate.
`K_(2) Cr_(2) O_(7) + 2 KOH rarr underset(yellow) underbrace(2K_(2) Cr O_(4)) + H_(2) O`
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Knowledge Check

  • The colour of K_2Cr_2O_7 changes from red orange to lemon yellow on treatment with aqueous KOH because of the _____________.

    A
    reduction of Cr(VI) to Cr(III)
    B
    formation of chromium hydroxide
    C
    conversion of dichromate to chromate
    D
    oxidation of potassium hydroxide to potassium peroxide.

  • K_(2)Cr_(2)O_(7)//H^(+) changes to green by

    A
    `Fe^(2+)`
    B
    `SO_(2)`
    C
    Both (a) and (b)
    D
    None of these

  • K_(2)Cr_(2)O_(7) is an example of

    A
    hexagonal
    B
    triclinic
    C
    cubic
    D
    Orthorhombic.

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