Sciencemadness Discussion Board

Potassium ferricyanide

KrahenAsher - 17-12-2013 at 08:14

Hello there..
Potassium ferricyanide can be manufactured by passing chlorine through a solution of potassium ferrocyanide:
2 K4[Fe(CN)6] + Cl2 → 2 K3[Fe(CN)6] + 2 KCl

My question is: How much of each reagent to work good?



You may ask: Why didn't you buy the potassium ferricyanide ready,safe & sound?
The answer: Here in my town, ferricyanide is ~$5,00 more expensive than ferrocyanide.. In small amounts there's no big deal, but in larges ones...

So, I'll be thankful if someone could tell me the amount of each reagent :)

WGTR - 17-12-2013 at 09:24

Quote: Originally posted by KrahenAsher  
The answer: Here in my town, ferricyanide is ~$5,00 more expensive than ferrocyanide.. In small amounts there's no big deal, but in larges ones...

So, I'll be thankful if someone could tell me the amount of each reagent :)


If a cylinder of chlorine lets loose in an urban area, you'd have to evacuate at least the city block around you, that is, if you
weren't already too busy coughing up your lungs in a bloody froth. For that reason, I would question the idea's practicality if
you intend to do this on a large scale.

chemrox - 17-12-2013 at 12:16

NRSMA: non-responsive school-marm answer. Don't you hate these?

WGTR - 17-12-2013 at 14:00

Now, now....if I was really a school-marm, my answer would have been, "Ferricyanide?!? Oh my goodness, cyanide is bad!!!"

Just for fun, here's a little tidbit:

phosgene_chlorine_ammonia_comparison.jpg - 53kB

IChemE, Jan 1, 1993 - Carbon oxychloride

Personally I'd rather handle a beaker full of phosgene than the several pounds of chlorine that's being implied. But hey, that's just me. If he
doesn't like my answer, he could try explaining how he's going to handle his chlorine to get a better one, or he can check with vulture to see
about getting a refund for his internet credits. :D

[Edited on 17-12-2013 by WGTR]

NexusDNA - 18-12-2013 at 09:42

Again, it is always good to remember these should be treated with respect; volatile and poisonous gases are dangerous not only to yourself, you see. I've had some bad times with potassium ferricyanide already, because of chloride impurity. It tends to pull water from the air and will eventually react, releasing even more noxius compounds. Just don't bring harm to anyone. Anyway, here is a good book on these compounds (K ferricyanide included):

The chemistry of cyanogen compounds and their manufacture and estimation, 1915, by Herbert E Williams. (there might be newer editions available)

DraconicAcid - 18-12-2013 at 14:06

You should be able to use other oxidizing agents to turn ferrocyanide into ferricyanide. Acidic hydrogen peroxide should work.