Sciencemadness Discussion Board

NaClO from TCCA

Kloberth - 14-9-2023 at 08:22

I did not find any other thread talking about this, but is it possible to prepare concentrated bleach from TCCA? In theory the TCCA should form hypochloric acid and isocyanuric acid when dissolved in water.

Pumukli - 14-9-2023 at 09:41

As far as I know the solubility of TCCA in water is not too spectacular to say the least. (A few percent comes to mind, but it is only my gut feeling.) On the other hand, even if you dissolve it in water you won't automatically get HOCl solution at the same time. There is a second (hydrolysis) step involved and that is a relatively slow process around pH 7.

[Edited on 14-9-2023 by Pumukli]

[Edited on 14-9-2023 by Pumukli]

Bedlasky - 14-9-2023 at 10:44

Make chlorine generator from TCCA and HCl, than bubble Cl2 in to the cold NaOH solution.

fx-991ex - 14-9-2023 at 12:29

Couldnt he use pool shock, calcium hypochlorite Ca(ClO2)2

Kloberth - 14-9-2023 at 13:55

i could but dont have it on hand

just wanted to know if there is a easy way to make it from stuff i already have

[Edited on 14-9-2023 by Kloberth]

Achilles - 19-9-2023 at 10:22

if you bubble chlorine through cold sodium hydroxide you have to deal with a solution full of sodium chloride and the solution is heavily corrosive/reactive even agains skin.

Bedlasky - 21-9-2023 at 05:26

NaOCl solutions always contain NaCl, they are always made frome chlorine and NaOH.

woelen - 21-9-2023 at 06:33

I doubt whether that still is true. In the past indeed such solutions were made from NaOH and Cl2, but nowadays I'm not sure about that.

When I was a teenager, I could buy powdered calcium-bleach, consisting of Ca(Cl)(OCl), which was made from Cl2 and Ca(OH)2. It was sold in supermarkets as bleaching powder. This powder had about 35% "active chlorine". Nowadays it is not sold anymore, but now we have Ca(OCl)2, without the chloride, with appr. 70% "active chlorine". The stuff we buy now is mainly used for swimming pools, but still also is used for bleaching purposes.

It might be that the same is true for bleach. Swimming pool bleach with 13% active chlorine may be mainly NaOCl in solution, with just a small fraction of NaOH and NaCl in it. I might be wrong, it may be an interesting experiment to check that. If you buy fresh high concentration bleach, then you could catalytically decompose all hypochlorite to chloride and oxygen and then determine the chloride concentration.

Chemgineer - 27-9-2023 at 11:50

Quote: Originally posted by woelen  
I doubt whether that still is true. In the past indeed such solutions were made from NaOH and Cl2, but nowadays I'm not sure about that.

When I was a teenager, I could buy powdered calcium-bleach, consisting of Ca(Cl)(OCl), which was made from Cl2 and Ca(OH)2. It was sold in supermarkets as bleaching powder. This powder had about 35% "active chlorine". Nowadays it is not sold anymore, but now we have Ca(OCl)2, without the chloride, with appr. 70% "active chlorine". The stuff we buy now is mainly used for swimming pools, but still also is used for bleaching purposes.

It might be that the same is true for bleach. Swimming pool bleach with 13% active chlorine may be mainly NaOCl in solution, with just a small fraction of NaOH and NaCl in it. I might be wrong, it may be an interesting experiment to check that. If you buy fresh high concentration bleach, then you could catalytically decompose all hypochlorite to chloride and oxygen and then determine the chloride concentration.


I recently bubbled chlorine through a saturated solution of NaOH, after my chlorine generator was done I had a nice yellow solution which I assume was sodium hypochlorite with NaOH and NaCl.

Now in the past I have used shop bought thin bleach to mix with acetone and produce some chloroform.

I tried the same with my prepared hypochlorite solution, I got the heat from the haloform reaction but I did not manage to get a clear layer of chloroform to settle out but ended up with a cloudy solution.

My guess is either the NaOH or the NaCl is interfering with it.

I could try running 2x Cl generators through it to reduce NaOH as much as possible if I decide to carry on with this,

I dissolved 181g of NaOH in 500ml of water and allowed to fully cool.
I then set up 250g of Sodium dichloroisocyanurate (pool granules) in a flask.
I placed an equalized dripping funnel over it with 420ml of 20% hcl and connected the top to tubing and a glass tube which was placed in the NaOH solution.

I'm not sure I will do this again as even working outside, when breaking down the apparatus the chlorine was evil!

[Edited on 27-9-2023 by Chemgineer]

fx-991ex - 27-9-2023 at 12:07

Store bought bleach has NaOH in it to stabilize.
An excess of NaOH should not stop the reaction.

j_sum1 - 27-9-2023 at 17:13

And yes. Chlorine is evil.

Tsjerk - 28-9-2023 at 02:23

Are you sure it is not chlorine that is interfering?