Question

What is the charge on the Cr in Cr2O72-

Answer 1

In the dichromate ion, the oxidation number of chromium is+6. The sum of the oxidation numbers in Cr2O72-, a polyatomic ion, is -2, the charge of the ion.

Answer 2

+6.

Step-by-step explanation:

So, a chromium atom here has an oxidation number of +6.