Re: Strange Redox Property of H2O2

farooq_w_at_hotmail.com
Date: 12/30/04 

Date: 30 Dec 2004 11:41:12 -0800

[All agreed upon]
> 2) Excess of ferrocyanide
> To a small volume of this alkaline hydroxylamine solution add a
fairly
> large amount of K4Fe(CN)6.3H2O. The solid dissolves and the liquid
> becomes pale yellow, due to high-concentration-ferrocyanide. Heat the
> liquid for a while and it becomes deep yellow. This probably is due
to
> formation of ferricyanide.

This interpretation is not very convincing. First, we can consider that
amount of hydroxylamine was negligible as compared to the amount of
ferrocyanide. Now if you remember that ferrous salt solutions do turn
slightly brown within minutes on exposure to air or by boiling...air
oxidation. Another source of error could be the water used to make the
solution, often it contains enough dissolved oxygen to oxidize air
sensitive (like Fe(II)) species. Run a control experiment, i.e a
ferrocyanide soln. containing nothing but water be boiled similarly,
does it turn deep yellow?

Its raining heavily here which rather surprising for us..its a good
omen for my thirsty plants.

>
> In the experiments, a continuous fizzling of a colorless gas can be
> observed. This probably is N2 from a disproportionation reaction of
> NH2OH to NH3, H2O and N2.