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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

Reduction of `Cr(VI)` to `Cr(III)`

B

Formation of chromium hydroxide

C

Conversion of dichromate into chromate ion

D

Oxidation of potassium hydroxide to potassium peroxide

Text Solution

Verified by Experts

The correct Answer is:
C
`K_(2)Cr_(2)O_(7)+2KOHrarr2K_(2)CrO_(4)+H_(2)O`
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P BAHADUR-REDOX REACTIONS-Exercise 3(A) Objective problems
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  2. Oxidation number of carbon in carbon sub-oxide is:

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  3. The colour of K(2)Cr(2)O(7) changes from red-orange to lemon-yellow on...

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  9. N(2) + 3 H(2) rarr 2NH(3) Molecular weight of NH(3) and N(2) are x(1...

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  10. Equivalent weight of FeC(2)O(4) during its reaction with KMnO(4) is:

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  11. The no.of electrons involved in the change, Fe(3)O(4)rarrFe(2)O(3):

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  12. How many gram of I(2) are present in a solution which requires 40 mL o...

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  13. What weight of FeSO(4) ( mol.wt. =152) will be oxidised by 200 mL of n...

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  14. 25 mL of 0.50M H(2)O(2) solution is added to 50 mL of 0.20 M KMnO(4) i...

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  15. What volume of O(2) measured at standard condition will be formed by t...

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  16. The number of Fe^(2+) ion oxidised by one mole of MnO(4)^(-) ions is:

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  17. What mass of HNO(3) is needed to convert 5g of the iodine into iodic a...

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  18. Number of K^(+) ions present in one litre of M//5KMnO(4) solution are:

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  19. When the ion Cr(2)O(7)^(2-) acts as an oxidant in acidic aqueous solut...

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  20. What volume of 3 molar HNO(3) is needed to oxidise 8 g of Fe^(3+), HNO...

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