What is the oxidation number of the chromium atom in K₂Cr₂O₇? A)-2 B)+2 C)+6 D)+7

Question

Quizplus · Accepted Answer

Firstly, we have to determine the oxidation state of the anion (polyatomic ion) which is Cr2O7 2-. 
Let the oxidation state of chromium be 'x'. 
The oxidation state of oxygen is -2 and there are 7 oxygen atoms. Therefore, the total oxidation state of oxygen is -2*7 = -14. 
Since the anion has a charge of -2, the sum of the oxidation states of Cr and O is -2. 
Therefore, x - 14 = -2 
x = +6. 
Hence, the oxidation state of chromium is +6.

What Is the Oxidation Number of the Chromium Atom in K2Cr2O7

What Is the Oxidation Number of the Chromium Atom in K₂Cr₂O₇