Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  
Author: Subject: Homemade HCL Bright Yellow
jmneissa
Harmless
*




Posts: 29
Registered: 4-5-2009
Member Is Offline

Mood: No Mood

[*] posted on 11-11-2009 at 10:28
Homemade HCL Bright Yellow


Hey guys so the other day I was synthesizing some HCL from tap water and hydrogen chloride gas by sulfuric acid salt method. Well after the reaction I was left with some reasonably strong and clear HCl. Now I have been away from my lab for about a week but open opening the chemical cabinet I saw that the HCL had turned bright yellow. My first thought was that there was a contaminate in the water that reacted with the HCL turning the solution yellow most likely iron. My question is does using yellow HCL in reactions especially washings effect the final product to a noticeable extent?
View user's profile View All Posts By User
1281371269
Hazard to Others
***




Posts: 312
Registered: 15-5-2009
Member Is Offline


[*] posted on 11-11-2009 at 10:46


It depends what the impurities are and how pure you need the final product to be - what sort of reactions will it be used for?.

I once left a molar solution of NaHCO3 / tap water in a glass bottle for a while and white flakes formed, which is presumably calcium carbonate and calsium and magnesium bicarbonates.

It's very cheap to buy distilled water although it's almost as cheap to buy HCl - which might be the best option.

[Edited on 11-11-2009 by Mossydie]
View user's profile View All Posts By User
psychokinetic
National Hazard
****




Posts: 558
Registered: 30-8-2009
Location: Nouveau Sheepelande.
Member Is Offline

Mood: Constantly missing equilibrium

[*] posted on 11-11-2009 at 11:33


Does your council fluoridate your water supply?



“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.
I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.”
-Tesla
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 11-11-2009 at 13:06


Jmneissa I know im just stating the obvious here but I feel it needs to be said. If you are going to attempt to perform any synthesis that uses H2O other then using it for a wash that will be tossed any way why not use bottled water? When using spring water you can even get the test results showing the percentage of contamination in the water if really needed. Its cheep enough that you should try to do another run with spring water and see if the yellow color still presents itself.




Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
Lambda-Eyde
National Hazard
****




Posts: 859
Registered: 20-11-2008
Location: Norway
Member Is Offline

Mood: Cleaved

[*] posted on 11-11-2009 at 14:01


In what sort of vessel did you store your clear hydrochloric acid? Rubber stoppers are attacked by HCl, rendering the stoppers black and the acid yellow-ish.
View user's profile View All Posts By User
Paddywhacker
Hazard to Others
***




Posts: 478
Registered: 28-2-2009
Member Is Offline

Mood: No Mood

[*] posted on 11-11-2009 at 14:28


Ferric chloride is a common contaminant in HCl. It distills with the HCl, so cannot be removed that way.
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 11-11-2009 at 14:48


I think Lambda-Eyde is correct here. . .
FeCl3 imparts a greenish hue to HCl!
Tap water would need to be visibly contaminated to produce coloured HCl. . .
View user's profile View All Posts By User
jmneissa
Harmless
*




Posts: 29
Registered: 4-5-2009
Member Is Offline

Mood: No Mood

[*] posted on 11-11-2009 at 15:01


Thanks for all the replies here are some answers. Firstly, yes my town does fluoridate there water. Secondly I did think about using bottled water but isn't it the same as tap water? Isn't all that media about how we should save money by using filters at home blah blah blah. I stored the HCL in a glass flask with a glass stopper. Thanks
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 11-11-2009 at 15:17


Some brands of table-salt contain various anti-caking agents---one is potassium ferricyanide possibly, though they would generally be in trace amounts. . .
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 11-11-2009 at 16:23


Quote:
Secondly I did think about using bottled water but isn't it the same as tap water? Isn't all that media about how we should save money by using filters at home blah blah blah. I stored the HCL in a glass flask with a glass stopper. Thanks


As far as tap water being like bottled water the answer is no not a chance. Much of what you here is enviromentist hype scared of plastic bottles being used and the rest is based on top notch water filters to remove the crap from tap water making it simular to bottled water. If this is a concern to you then by distilled water at the store. Its not much more and ensures low contamination. It can be found in the baby isle if no where else albeit at a higher cost. The fact that you mentioned your city fluoridating your drinking water should have answered your question as to wether or not it is the same as bottled water.

Attempt to wash out your glass with HCl prior to storing the main portion to make sure you have no soluble reactants on the glass. I do not believe your issue is a big one when it comes to using it for synthesis but since you asked for purity I thought I would mention some ways to ensure it.

~Sedit







Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
Sedit
International Hazard
*****




Posts: 1939
Registered: 23-11-2008
Member Is Offline

Mood: Manic Expressive

[*] posted on 11-11-2009 at 16:23


Quote:
Secondly I did think about using bottled water but isn't it the same as tap water? Isn't all that media about how we should save money by using filters at home blah blah blah. I stored the HCL in a glass flask with a glass stopper. Thanks


As far as tap water being like bottled water the answer is no not a chance. Much of what you hear is enviromentist hype scared of plastic bottles being used and the rest is based on top notch water filters to remove the crap from tap water making it simular to bottled water(which many companys are ripping people off using the same filters and claiming spring water). If this is a concern to you then buy distilled water at the store. Its not much more and ensures low contamination. It can be found in the baby isle if no where else albeit at a higher cost. The fact that you mentioned your city fluoridating your drinking water should have answered your question as to wether or not it is the same as bottled water.

If you wish attempt to wash out your glass with HCl prior to storing the main portion to make sure you have no soluble reactants on the glass. I do not believe your issue is a big one when it comes to using it for synthesis but since you asked for purity I thought I would mention some ways to ensure it. If nothing else it will be a good excercise in cleanliness.

~Sedit




[Edited on 12-11-2009 by Sedit]





Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 11-11-2009 at 17:30


hissingnoise had similar thoughts to mine. If you used table or kitchen salt, it often has both sodium ferrocyanide and iodides or iodates added to it.

Such salt may also have small amounts of organic substances, there are brands of salt that have sugar added to them for example. These could reduce any Fe(III) to Fe(II), carry-over of that iron in spray (if a simple distillation setup was used) would give only a slight greenish tint to the product, but air oxidation to Fe(III) would give the stronger yellowish colour of the chloride complex of ferric iron.
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 8011
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 11-11-2009 at 23:40


Even clean-looking glass can give off quite some yellow color in HCl. I sometimes buy glassware from eBay and even when it looks clean I many times see that colorless HCl turns yellow when I rinse the glassware with this acid. Apparently there is a very thin invisible film of crap inside the glass which gives visible contamination to the HCl. It might be that your bottle suffered from the same issue. So, the best is to rinse the bottle before storage of HCl with some dilute H2SO4/NaCl mix (or some of your yellow HCl) and then with some distilled water.



The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
jmneissa
Harmless
*




Posts: 29
Registered: 4-5-2009
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 08:17


Thanks for the info guys. Some notes for next time I guess. Firstly wash out glassware with HCL and then distilled water to remove unseen contaminants. Secondly use bottled water or filtered water in reaction vessel. Thirdly, try and find some pure salt without additives. I wonder is the kosher salt they sell at the store would work or sea salt I think would also work. Let me know if I missed anything.
View user's profile View All Posts By User
bbartlog
International Hazard
*****




Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 09:11


Quote:
or sea salt I think would also work


This would be pretty much the opposite of 'pure salt without additives'. Commercial salt may have some anti-caking agent and small amounts of iodine compounds, but sea salt will have a multitude of compounds above and beyond that. Look at the composition of seawater to get an idea. Granted it's still mostly chlorides, and if all you're doing is H2SO4+NaCl to produce HCl then having some MgCl in the mix won't matter, but there's also small amounts of sulfur, bromine and many other things.
View user's profile View All Posts By User
jmneissa
Harmless
*




Posts: 29
Registered: 4-5-2009
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 09:40


yes while that is true it is mostly chlorides and does not have any the anti-caking agents that most likely caused the problem in the beginning. It is sort of the least of all evils.
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 12-11-2009 at 09:41


One of those other things being gold---extraction by electrolysis was seroiusly considered at one time by many eminent scientists who should have known better.
I consider sea-salt the superior condiment though, possibly because it's so mineral-rich. . .
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 10:02


Quote:
Secondly use bottled water or filtered water in reaction vessel

No, use deionised or distilled water. Bottled or filtered addresses stuff that might be harmful to you, not chemical purity. Distilled water isn't the best water for drinking purposes, the WHO recommends that water for consumption contain a certain amount of calcium and magnesium salts.

Canning salt is non-iodised, in fact some table salt is also and wil be so labeled. Kosher salt is so named because of its use in making meats kosher be pulling out the blood. The grain shape determines this, kosher salt has relatively large flat grains. It may or may not contain additives, read the label.

View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 12-11-2009 at 10:09


Canning salt too, may have added ingredients to help with the process of canning, but as I said upthread the amounts of anti-caking agents in table-salt should be relatively minor and I would be surprised if they were the culprit. . .
KCl might be better for HCl, though. . .or. . .some other chloride salt!

[Edited on 12-11-2009 by hissingnoise]
View user's profile View All Posts By User
bbartlog
International Hazard
*****




Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 10:45


One advantage of using CaCl2 instead of NaCl or KCl is that excess remaining H2SO4 (that you might want to reuse) should be easily separated from the precipitated gypsum. Separating Na2SO4 from H2SO4 would be a fair bit more difficult. Bulk CaCl2 is cheap, too, though it's probably even less pure than table salt.
Not planning to try that myself, though. 31% HCl is very cheap at the local hardware store (given that it's basically a repurposed industrial waste, that's not too surprising).
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 12-11-2009 at 10:52


Of course, using the Na or K salt leaves you with the bi-sulphate which has other uses.
Na2SO4 isn't normally formed at the temperatures used for HCl preparation.
View user's profile View All Posts By User
jmneissa
Harmless
*




Posts: 29
Registered: 4-5-2009
Member Is Offline

Mood: No Mood

[*] posted on 12-11-2009 at 14:38


Okay thank so I will use distilled or deionized water in my next experiment and try to fine some "pure" salt that is non iodized and contains no other ingredients. The one place that has occurred to me to look for this is the water softening section of stores because I know they sell big bags of KCl but do not know its relative purity.
View user's profile View All Posts By User
hissingnoise
International Hazard
*****




Posts: 3940
Registered: 26-12-2002
Member Is Offline

Mood: Pulverulescent!

[*] posted on 12-11-2009 at 14:43


Muriate of Potash fertiliser is cheap, comes in prills and the outer moisture-repelling layer is practically insoluble. . .
The prills can be dissolved, filtered and evaporated leaving the equivalent of tech. grade KCl!
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 8011
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 16-11-2009 at 03:08


Buy the cheapest table salt you can find in a super market, which is a free flowing fine crystalline mass. That is very pure NaCl and the only additive (if any) will be a tiny tiny amount of anticaking agent (appr. 0.001% of potassium ferricyanide is added for this purpose, sometimes simply some tenths of percents of CaCO3 is added for this purpsoe). All the fancier and more expensive stuff contains a lot of other things like iodide, other minerals and even some added flavors.



The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 16-11-2009 at 18:10


Depends on which country you are in. I know from experience that in some the lowest priced food salt costs the same with or without added iodine in some form, and contains the same anti-caking substances.

Course grain salts, such as kosher and canning, often have no additives but the trace of ferricyanide used to control crystal size and shape in the crystallisation step. Finer grain forms of salt often have additional anti-caking additives, some such as the aluminosilicates won't cause problems for making HCl, others might.

View user's profile View All Posts By User
 Pages:  1  

  Go To Top