What is the charge on the cation (#Fe#) if the formula of an ionic compound is #FeS_2#?

1 Answer
Jul 22, 2018

Well, sulfur, a Group 16 atom, commonly forms a....

Explanation:

...commonly forms a #S^(2-)# ion, i.e. #"the sulfide ion"#

And so we have likely got an #Fe(+IV)# salt....

Less commonly, we could form a #"persulfide ion"#, i.e. #S_2^(2-)#...the which would specify an #Fe^(2+)# salt...but I don't know which scenario applies here. #"Persulfide ion"#, #""^(-)S-S^(-)# is an analogue of #"peroxide ion"#, #""^(-)O-O^(-)#. The oxidation states for both sulfur and oxygen are #-I#...