## HW Question 17.31

Alejandra Reyna 1E
Posts: 18
Joined: Wed Sep 21, 2016 2:58 pm

### HW Question 17.31

The problem states to write the formula for each coordination compound. My confusion is with parts C and D.

Part C: tetraamminediaquacobalt(III)bromide
Formula -> [Co(NH3)4(H2O)2]Br3

Part D: sodium bisoxalato(diaqua)ferrate(III)
Formula -> Na[Fe(OH2)2(C2O4)2]

I noticed both C and D contain diaqua but one is H2O and the other is OH2. When is it required to use one over the other?

Chem_Mod
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### Re: HW Question 17.31

Interesting question.

I mentioned this when drawing coordination compounds in class.

We accept both in the formula.
The reason for reversing the water when it is written next to the transition metal cation is to make it clear that the oxygen atom bonds to the transition metal.

Jacinda Wollenweber 1D
Posts: 22
Joined: Wed Nov 16, 2016 3:02 am

### Re: HW Question 17.31

For part b of this question, which is pentaamminesulfatocobalt (III) chloride, how do we find the number of chlorines needed?

004744172
Posts: 15
Joined: Fri Jun 23, 2017 11:39 am

### Re: HW Question 17.31

Jacinda Wollenweber 1D wrote:For part b of this question, which is pentaamminesulfatocobalt (III) chloride, how do we find the number of chlorines needed?

Correct me if I'm wrong but because there are 5 NH3 (0x5=0),one sulfato (-2x1), and cobalt has a charge of 3, the inside brackets will equal 1. What is outside the brackets must be the opposite. For example, inside is positive one so that means the outside is negative one. Hope that helped.

Michelle Steinberg2J
Posts: 73
Joined: Fri Sep 29, 2017 7:04 am

### Re: HW Question 17.31

In this question, does it matter the order of the elements within the brackets? My order is different than that in the solutions manual, does that make it wrong?

I have just been putting them in order based on the name provided, taking it step by step, but after I have determined the elements and the number associated with them should I be putting them in a specific order within the brackets?

Hopefully my question makes sense. Thanks.