What is the oxidation number of chromium in #[Cr(NH_3)_4Cl_2]Cl#?
This is clearly
So how do we know this?
First let's remove the chloride counterion:
Chromium is still 6-coordinate, but because we conserve charge when we remove
And then we remove
And thus we have
Now obviously I have made a meal of this as a method of emphasis. All I have really done is conserve charge througout.
Can you tell me the oxidation number of the metal in