Sciencemadness Discussion Board

Breaking Down Chemical Solution

Chemcrazyman - 24-9-2011 at 13:08

Hi all,

I am newer to the chemistry game and excited to have found this site. I was wondering how hard it is to break down a chemical solution. For example, I know the chemicals are ferrous chloride, hydrochloric acid, and sodium dichromate, but I don't know the proportions used of each to create the solution.

I want to create the solution to to stain my small patio a brownish color. Am I correct that the mixture could create a brownish color? Should I simply safely experiment the combinations or can it be broken down?

Thanks for all the help. Much appreciated.

Endimion17 - 24-9-2011 at 13:30

What exactly do you mean when you say "break down"?

BTW dichromates are carcinogenic. They belong in the lab... not the environment. If you want to stain your patio, you can always buy some brown paint. Or use a torch...

LanthanumK - 24-9-2011 at 13:41

Just the application of ferrous chloride mixed with some sodium carbonate should produce green ferrous hydroxide, which should turn brown through oxidation and stain your patio brown. The oxygen in the air provides all the oxidation necessary - no need for dichromates.

plante1999 - 24-9-2011 at 13:45

Simply ad iron II acetate.... it will turn black and if you ad hydrogen peroxide or carbonate after , it will turn brown.

It is a real process for wood worker.

Chemcrazyman - 24-9-2011 at 14:49

thanks for the advice. I will stay away from sodium dichromate. I knew it was a carcinogen, but thought it was necessary in producing stain due to companies msds.

rstar - 26-9-2011 at 20:42

Simply pour a solution of Potassium permanganate, and some reducing agent that can reduce it to MnO<sub>2</sub>, and it will be a brown stain, but the process might be costly. :D

Chemistry Alchemist - 26-9-2011 at 20:50

Doesnt Potassium Permanganate stain everythng brown even with out a reducer? when im using a solution of the stuff in glass ware, i always seem to have a brown stain where the solution was ><

Chemistry Alchemist - 26-9-2011 at 20:54

Quote: Originally posted by Chemcrazyman  
Hi all,

I am newer to the chemistry game and excited to have found this site. I was wondering how hard it is to break down a chemical solution. For example, I know the chemicals are ferrous chloride, hydrochloric acid, and sodium dichromate


did u say u have Sodium Dichromate? or were u going to buy some for the solution?

rstar - 26-9-2011 at 21:02

Quote: Originally posted by Chemistry Alchemist  
Doesnt Potassium Permanganate stain everythng brown even with out a reducer?


Oh Yes,
that's correct, there is no need of reducer ;)

Chemistry Alchemist - 26-9-2011 at 21:06

its a pain in teh ass cleaning the stains off beakers when i leave it in for too long... my sink is stained aswell, how would i clean it all off?

rstar - 26-9-2011 at 21:18

Quote: Originally posted by Chemistry Alchemist  
how would i clean it all off?


Use Hydrochloric acid to remove MnO<sub>2</sub> stain.
4HCl + MnO<sub>2</sub> = MnCl<sub>2</sub> + 2H<sub>2</sub>O + Cl<sub>2</sub>

Be careful !! it produces Chlorine :D

Chemistry Alchemist - 26-9-2011 at 21:22

So correct me if im wrong, but if it is MnO2 thats has latched onto the glass causing a stain, what happens to the KMnO4? does that get reduced to green manganate or what? becuase if its loosing MnO2 onto the glass, there must be somthing happening the solutiion if u get what i mean

rstar - 26-9-2011 at 21:33

I haven't thought about that :o

Yeah, it may have became K<sub>2</sub>MnO<sub>4</sub> after decomposition.
And that would have reacted with water, to become KMnO<sub>4</sub> again.

3K<sub>2</sub>MnO<sub>4</sub> + 2H<sub>2</sub>O = 2KMnO<sub>4</sub> + MnO<sub>2</sub> + 4KOH

Chemistry Alchemist - 26-9-2011 at 22:28

Does green Manganate disproportionate to form MnO2 and KOH, i made same and left it to dry, i suddenly had a clear solution and a brown precipitate.... is it KOH and MnO2?

rstar - 29-9-2011 at 03:27

Quote: Originally posted by Chemistry Alchemist  
Does green Manganate disproportionate to form MnO2 and KOH, i made same and left it to dry, i suddenly had a clear solution and a brown precipitate.... is it KOH and MnO2?


NO...
It disproportionate to KMnO4 and MnO2.

"In a disproportionation reaction, one reactant (in this case, K2MnO4) forms an oxidized(KMnO4) and reduced(MnO2) product."

K2MnO4 does not disproportionate on its own, but it done by the reaction with water, so another product is the Hydroxide ion, which is comes out as KOH

[Edited on 29-9-2011 by rstar]

[Edited on 29-9-2011 by rstar]