Waiting for answer This question has not been answered yet. You can hire a professional tutor to get the answer.

QUESTION

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

+6

Problem: What is the oxidation number (O.N.) of chromium (Cr) in the dichromate ion "Cr"_2"O"_7"^(2-)?

Let the O.N. of Cr be x. The O.N. of oxygen is -2.

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 "2"^-, as indicated by its formula, "Cr"_2"O"_7"^(2-).

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

2*x - 14 = -2

Add 14 to both the sides;

2*x -14 +14 = -2 +14

2*x = 12

Divide both sides by 2 ;

"2x"/2" ="12"/"2"

x = 6

The oxidation number of chromium in the dichromate ion is +6.

Here is a video which discusses this question.