Does the Charge on NOS Affect the Charge on Fe?

[mooncrater]

Homework Statement

There is a reaction given in my textbook which says:
$Na_2S+Na_2 [Fe(CN)_5 (NO)]$ $\longrightarrow$ $Na_4 [Fe (CN)_5 (NOS)]$
I know initially Fe is in +2 state.
But does it become +3 charged after the reaction? What is the charge on NOS? Is it $NOS^{-1}$ or $NOS^{-2}$?

Homework Equations

The Attempt at a Solution

I don't know... charge on $Fe$ depends upon the charge on $NOS$... which I don't know.
Any help appreciated.

 

[James Pelezo]

I don't know how much I can help without getting castigated by admin, but I will risk it... The [Fe(CN)₅(NO)] = -2 net charge and [Fe(CN)₅(NOS)] = -4 net charge. Both are octahedral coordination structures with Fe⁺⁴ + 2e^- => Fe⁺² as the reduction and sulfur in Na₂S is -2 charge being oxidized to S^o in the -NOS structure. Both -NO and -NOS have the same oxidation states = -1. Look up octahedral geometry, place CN (= -1 charge) on all points in the plane and one above the plane. The -NO and - NOS are each below the plane. With all the points -1 = -6 and Fe⁺⁴ in the reactant side = net -2 for the reactant anion. Draw the same structure with all points -CN and one -NOS => -6 again on the product side, but Fe in the product structure is +2. Then [(-6) + (+2)] = -4 for the product anion structure. Hope I don't get fussed at. Good luck.

 

[mooncrater]

Thanks for your reply. I had some doubts:
$Fe$ has two stable states... $Fe^{+2}$ and $Fe^{+3}$. From where $Fe^{+4}$ came? Originally the compound has $Fe^{+2}$.

 

[James Pelezo]

Thanks for your reply. I had some doubts:
$Fe$ has two stable states... $Fe^{+2}$ and $Fe^{+3}$. From where $Fe^{+4}$ came? Originally the compound has $Fe^{+2}$.

+2 and +3 oxidation states for iron are the most common, but actually, iron can have eight (8) oxidation states depending on the compound and structure it is associated with... Here's a link that may help on this... http://en.wikipedia.org/wiki/Iron ... Scroll down to 'Atomic Properties', there will be a list of the possible oxidation states for iron.

Did you look up the octahedral geometry for coordination compounds? Follow my suggestion about placing the substrates as suggested, then check the net charges.

 

[James Pelezo]

Here's Iron in an Octahedral Geometry for FeCl^3-. The [Fe(CN)₅(NO)]^2- and [Fe(CN)₅(NOS)]^4- follow the same configurations.

 

[James Pelezo]

Homework Statement

There is a reaction given in my textbook which says:
$Na_2S+Na_2 [Fe(CN)_5 (NO)]$ $\longrightarrow$ $Na_4 [Fe (CN)_5 (NOS)]$
I know initially Fe is in +2 state.
But does it become +3 charged after the reaction? What is the charge on NOS? Is it $NOS^{-1}$ or $NOS^{-2}$?

Homework Equations

The Attempt at a Solution

I don't know... charge on $Fe$ depends upon the charge on $NOS$... which I don't know.
Any help appreciated.

Hey guy, how you doing on the problem? Just checking if all is OK. Hope I've helped. jp