The oxidation state of chromium in k2cr2o7 is +6.
The oxidation state of potassium is +1, while the oxidation state of oxygen is -2. So, potassium ions have a total charge of +1(2) = 2, whereas oxygen ions have a charge of 2(7) = 14.
Let x be the chromium’s oxidation number.
We can express the equation as follows:
2+ x- 14 = 0
-12 + x = 0
x = 12
The oxidation number of two chromium atoms is thus +12
So, each chromium atom has an oxidation number of 12 / 2 = 6.
Therefore, the Cr oxidation number in K2Cr2O7 is +6.