[skibum143]

Give systematic names for the following formulas. (Type your answer using the format copper(II) chloride for CuCl2.)
(a) [Cr(CO)5Cl]Br2
pentacarbonyl chloro cromium(III) bromide
(b) [Co(NH3)4(NO2)2]Cl
tetraammine binitrite cobalt(III) chloro
(c) Ba5[AuI6]2
pentabarium hexaiodo gold(I)

What are the formulas for each of the following coordination compounds? (Type your answer using the format [Co(NH3)6]Cl3 for [Co(NH3)6]Cl3. If necessary, use the abbreviation en for ethylenediamine. You can click on the eye icon to see your formatted answer.)
(a) tris(ethylenediamine)chromium(III) perchlorate
[Cr(en)3]^+2Clo4^-
(b) strontium hexachloroferrate(III)
Sr[Fe(Cl)6]^-

Not sure what I'm doing wrong on these, thanks for the help.

[JustinCh3m]

(a) tris(ethylenediamine)chromium(III) perchlorate

en = neutral ligand.  So, think about how you'd balance the complex ion's charge of +3 with perchlorate (the counterion) charge.

(b) strontium hexachloroferrate(III)

is it true that you've written your answer as having an overal -1 charge?  Realizing that the chloro ligands are each -1, think about how to balance the Sr +2 charge with the resulting overall charge when combining Fe+3 with it's 6 chloro ligands