$$\ce{NO3- + 3[Fe(H2O)6]^{2+} + 4H+ -> NO + 3[Fe(H2O)6]^{3+} + 2H2O}$$

$$\ce{NO + [Fe(H2O)6]^{2+} -> [Fe(NO)(H2O)5]^{2+} + H2O}$$

I read that in the brown ring complex $\ce{[Fe(NO)(H2O)5]^{2+}}$ , $\ce{NO^{-}}$ is the ligand.

What I don't understand is that :

How is $\ce{NO^{-}}$ formed? Nitrate ion got reduced to NO while $\ce{Fe^2+}$ was oxidized to $\ce{Fe^{3+}}$. The electrons that were released in the conversion of ferrous to ferric ion were used in converting nitrate ion to $\ce{NO}$. So where do these extra electrons come up that convert $\ce{NO}$ to $\ce{NO^{-}}$ ? I don't want to go into the mechanism; I just want to have an intuitive understanding of what's happening in the reaction.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.