posted by ... .
Charges on the metal
MgSO4 = +2
NiSO4*6H2O = +2
CoCl2*6H2O = +2
KCr(SO4)2*12H2O = +3
CuSO4*5H2O = +2
(NH4)2Cr2O7 = +2
FeSO4*7H2O = +2
MnCl2*4H2O = +2
FeCl3*6H2O = +3
I'm not sure if the above answers are correct, could someone please check them over and let me know?
You missed two; Cr alum and (NH4)2Cr2O7.
KCr(SO4)2. I think they wanted BOTH K and Cr but those are not +3 anyway you stack it. K is +1, Cr is +3, and that balances the -2 each for sulfate for a total of -4.
NH4 is +1 so two of them are +2.
O is -2 and seven of them are -14
Therefore, total Cr must be +12 (+12+2=14 which balances -14) so each Cr must be +6.
wow, those ones are confusing...