# What is the oxidation state of chromium in the dichromate ion, #"Cr"_2"O"_7^(2-)#?

##### 1 Answer

Nov 27, 2014

#### Answer:

+6

#### Explanation:

Problem: What is the oxidation number (O.N.) of chromium (Cr) in the dichromate ion

Let the O.N. of Cr be

The sum of the oxidation states in an ion must add up to the charge on the ion. The dichromate ion has a charge of

Add 14 to both the sides;

Divide both sides by 2 ;

The oxidation number of chromium in the dichromate ion is

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