Question

Calculate the oxidation number of
Cr in Cr2O7²-

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Answer 1

Answer:

The oxidation number of Cr in Cr2O7²- is +6

Explanation:

Cr2O7²-

Oxidation number of O is -2

Let the oxidation number of Cr be x.

2 (x) + (-2) (7) = -2

2x + (-14) = -2

2x - 14 = -2

2x = 14 - 2

2x = 12

x = 12/2

x = +6

Answer 2

Let oxidation number be x.

Net charge on the radical = -2

We know that, oxidation state of Oxygen is -2.

=> 2*x -2*7 = -2

=> 2x -14 = -2

=> 2x = 14-2

=> 2x = 12

=> x = 12/2

=> x = 6

=> x = +6

Hence, the oxidation state of Chromium in the Dichromate radical is +6.

It contains the strongly oxidizing Hexavalent Chromium.

This Hexavalent Chromium gives compounds containing it a bright to dull red or orange colour.