In MnCr₂O₇,the oxidation number of chromium is A)+2 B)-2 C)+12 D)+6

Question

Quizplus · Accepted Answer

In this compound, the oxidation number of sulfur is -2 and the oxidation number of oxygen is -2. 
The sum of the oxidation numbers of all the atoms in the compound must equal 0 (since it is a neutral compound). 
Let x be the oxidation number of chromium. 
So we have:
x + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 + (-2) + 1 = 0
Simplifying this gives:
x - 18 = 0
x = +18
Therefore, the oxidation number of chromium is +6.

In MnCr2O7,the Oxidation Number of Chromium Is

In MnCr₂O₇,the Oxidation Number of Chromium Is