Preparation and naming of coordination compounds

[Rujano]

Homework Statement

Hi.
The combination of Fe(II), H2O, Cl- y NH4+ yields 3 coordination compounds, one of which is:

[Fe(H2O)6]Cl2

Which are the other ones?

Homework Equations

The Attempt at a Solution

Even though I sort of know how the compounds could be formed I don't why or rather , how can I tell that only 3 will be formed...

For instance, I think that some of the compounds could be:

(NH4)3[Fe(H2O)Cl5]

[Fe(H2O)3Cl3]Cl

(NH4)2[Fe(H2O)2Cl4]

How can I tell if they are correct? and how can I know that they should be three for example (in this case I already have four :S)

 

[AGNuke]

If you are talking about the co-ordination Number 6, then the following possibilities are there with Co-ordination Sphere:

1. Have +2 charge; [Fe(H₂O)₆]Cl₂
2. Have +1 charge; [Fe(H₂O)₅Cl]Cl
3. Have 0 charge; [Fe(H₂O)₄Cl₂]
4. Have -1 charge; NH₄[Fe(H₂O)₃Cl₃]
5. Have -2 charge; (NH₄)₂[Fe(H₂O)₂Cl₄]
6. Have -3 charge; (NH₄)₃[Fe(H₂O)Cl₅]
7. Have -4 charge. (NH₄)₄[FeCl₆]

See, I formed 6 or 7 compounds, So what could you be asking that the compulsory presence of mentioned species, either inside or outside the sphere. Then there can be 3.

Also, there's no way to tell what will happen until you write down all possible cases.