I keep getting the wrong answer. Please advise how an oxidation number of +7 is obtained. An explanation would be greatly appreciated.
Please note: all the numbers are subscripts.
Please note: all the numbers are subscripts.
-
Well, since Ca(ReO4)2 is balanced, that means (ReO4)2 has a net charge of -2 to balance calcium's +2. Since oxygen has an oxidation number of -2 in the presence of a metal, and because each atom is multiplied by 2, the net charge from oxygen should be: -2 * 4 * 2 = -16. Since the overall charge is -2 and there are 2 rhenium ions, the overall charge from the rhenium ions has to be +14, or +7 for each rhenium ion. Hence, the oxidation number of rhenium is +7.
-
Oxygen is (almost) always -2. there are 8 oxygens so that = -16
Calcium is +2, there is one Ca so that = +2
So Re has to neutralize -14. There are two Re, so that's +7 each
Calcium is +2, there is one Ca so that = +2
So Re has to neutralize -14. There are two Re, so that's +7 each