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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: jamesslack on September 06, 2009, 10:34:46 PM

Title: hydrosulfuric acid
Post by: jamesslack on September 06, 2009, 10:34:46 PM
where can i buy hydrosulfuric acid, so i can tone my coins. i tryed the acid you clean brick with and the acid thats in a car battery but its not like hydrosulfuric acid. i guess you can use hydrogen sulfide but its a very poisonous gas, i use liver of sulfur right now but i got a book on coin chemistry and it said i could use this other stuff but i cant fined it. any help would be great, thanks
Title: Re: hydrosulfuric acid
Post by: Borek on September 07, 2009, 02:46:28 AM
You won't buy it as a solution. You may buy sulfides, you may buy thioacetamide. These are used in labs as a source of H2S.

Don't ask me where, as all I have at hand are Warsaw addresses that will be of no use.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 07, 2009, 11:31:16 AM
thanks for your time.
Title: Re: hydrosulfuric acid
Post by: MarZ on September 10, 2009, 08:36:40 AM
You may try Sodium Hydrogen sulphate crystals which makes an acidic solution of H2SO42- ions. This used to come with Chemistry sets as replacment reagent of dilute Acid. Also included was Sodium Hydrogen Sulphite which might be useful for your use.

Side note - check about cleaning coins with electrolysis!
Title: Re: hydrosulfuric acid
Post by: Borek on September 10, 2009, 09:16:26 AM
H2SO42-

Huh?
Title: Re: hydrosulfuric acid
Post by: MarZ on September 10, 2009, 09:59:30 AM
 :P oops - HS04-
A 1M solution will have a pH of 1.4.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 10, 2009, 10:35:36 PM
so Sodium Hydrogen Sulphite  would tone my silver like liver of sulfur.
Title: Re: hydrosulfuric acid
Post by: MarZ on September 11, 2009, 02:59:38 AM
I do not know, never tried but I wanted to give you an alternative idea since it is much more easy to find buying the reagents I suggested than hydrosulphuric acid. Sodium Hydrogen sulphite is used as an additive and I am sure is easy to find and cheap. It is used in Wine making for sure.  Google a bit around.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 11, 2009, 08:56:36 PM
ok i order the Sodium Hydrogen Sulphite i sure hope it works, heres what im going to do, let me know if you think its not safe. im going to put the Sodium Hydrogen Sulphite in a tube with alittle water and heat it so a gas will come off it. i will have a cover on the tube with a hose comeing out of it and going into a jar with my coin init to see if it tones my silver coin.
Title: Re: hydrosulfuric acid
Post by: Borek on September 12, 2009, 04:07:16 AM
I doubt sulfite will work the way you want it.

Honestly, I have just reread the thread and I doubt sulfuric acid will work either. I suppose you want your coins to be covered with oxides/sulfides - and neither of the sulfur oxyacids seems to be the right thing to use. But I can be wrong.
Title: Re: hydrosulfuric acid
Post by: MarZ on September 12, 2009, 08:01:05 AM
I just tried a coin in Sodium Hydrogen Sulphate (not sulphite) solution (quickly a pich of the salt in 10ml water)  for the sake of this post and after 1 hour, I could see big improvement on the condition of the coin, but I do not know the long-term effect. 

Disclaimer: Please note that I just wanted to give you an alternative reagent to Sulphuric Acid not that Sodium Hydrogen Sulphite clean coins for sure!
Title: Re: hydrosulfuric acid
Post by: billnotgatez on September 12, 2009, 08:13:26 AM
Does any of this stuff deteriorate the coin? Do you need to wash off the coin after use to prevent deterioration? Can you thoroughly wash it off and will the washing process be benign?
Title: Re: hydrosulfuric acid
Post by: Borek on September 12, 2009, 08:49:56 AM
so i can tone my coins

What effect do you have in mind, and what material are these coins made of. Do you want o clean them, or do you want to make them look old. Are they copper/bronze/brass, or silver or even some other material?
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 09:13:06 AM
the coin will be silver, and i want to tone the coin with pretty colors by using a gas type chemical. right now i use liver of sulfur to tone my coins, here's a picture of the silver coin.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 11:49:08 AM
heres a coin toned by useing a gas, but people wont tell you how they do it. so i got to try everything i can think of trying. the only people i know that would know how to do this is the smart people on this site that know what certain chemicals do. i know not a thing about chemicals but will keep trying with things i read. heres a picture of a pretty silver coin toned with a gas put to it in a jar and let it set for about 1-week to get the colors
Title: Re: hydrosulfuric acid
Post by: Borek on September 12, 2009, 12:50:12 PM
Thin layer of sulfide. Color visible is IMHO due to the same effect you see when there is a gas drop put on the water.

Gaseous hydrogen sulfide will be probably most effective. Look for thioacetamide, it decomposes when heated and produces H2S.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 01:47:37 PM
thank you very much i will try to buy some.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 03:13:41 PM
i think i found it,THIOACETAMIDE, REAGENT, ACS - 25 GM  would this be it.
Title: Re: hydrosulfuric acid
Post by: Borek on September 12, 2009, 04:16:53 PM
Name sounds correct. Put a little bit in water, and heat - it will hydrolize and stink as hell.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 04:48:06 PM
i thank you again, i have been working on this for months now.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 12, 2009, 08:20:01 PM
also do you need to wear a gas mask when turning this into a gas. or just be in a well ventilated area
Title: Re: hydrosulfuric acid
Post by: MarZ on September 13, 2009, 12:07:18 AM
From my side I can confirm that SOdium Hydrogen Sulphate solution cleaned the coin nicely but did not form the colourful effect.  At the beginning of the thread it seemed you wanted to clean coins with some mild form of Sulphuric acid.  I agree with Borek's suggestion and precautions. If at home, I would try this under ventilation extraction over cooker/oven at your kitchen (if you have one), else outdoors.
Title: Re: hydrosulfuric acid
Post by: Borek on September 13, 2009, 03:58:44 AM
Outdoors, or in some half open structure. You don't want to smell hydrogen sulfide at home.

Note, that hydogen sulfide is treacherous - it stinks like hell in lower concentrations, but it somehow paralyzes (in the lack of better word in my English) the nose cells in concentrations in which it is really dangerous.

But then, using just a pinch of thioacetamide, you are on the safe side. Just remember to either warn your neighbors or try it far from the buildings :)
Title: thioacetamide
Post by: jamesslack on September 25, 2009, 09:18:59 PM
the thioacetamide i got does not smell like rotten eggs or is there a smell to it, would this be a bad batch. i put some in a jar and i will let set for acouple of days to see if i get toneing on my silver coin. i put water and thioacetamide in a test tube and heated it up so the steam would go up the hose and into my other jar with the coin init. but the first time i tryed it i let the jar set for a day and tooked the lid off and there was no smell at all. heres a picture of the bottle that the companie sold me.
Title: Re: thioacetamide
Post by: renge ishyo on September 25, 2009, 09:36:24 PM
You shouldn't be sniffing chemicals  :-X

But yeah, according to the MSDS, thioacetamide has a very mild smell.
Title: Re: thioacetamide
Post by: jamesslack on September 25, 2009, 09:53:09 PM
on my old post that i listed which is 12 post below this one hydrosulfuric acid i was told it would stink very bad that's why i thought maybe i had something that wasn't working.  boy i really wish i was a chemest so i would know all this stuff.  sorry for bugging you chemest.
Title: Re: thioacetamide
Post by: jamesslack on September 25, 2009, 10:14:41 PM
i was also told i could make the H2S gas with black salt sulfur and a toilet bowl cleaner called the works but you got to use 2lbs of the salt and five bottals of the works which is way to much stuff to mix to tone a coin, but i think making it that way is way to dangers.
Title: Re: thioacetamide
Post by: renge ishyo on September 25, 2009, 11:32:09 PM
Oh i see...you should have just replied in that thread; it would have bumped it to the top and helped with the clutter  ;)

Yeah thioacetamide itself doesn't stink, but it releases H2S which smells like rotten eggs (and is extremely toxic so don't breathe in much and make sure you do this in a place with good ventilation).

It is hard to tell from your setup if the H2S didn't react with your coins already which would explain why you didn't smell anything after a day or so. To test for the quality of your thioacetamide I suggest following Borek's adivice by taking a tiny amount of thioacetamide and dissolve it in water (no fancy appratus), and heat it up on it's own out in the open air to test for the production of H2S fumes. Once you smell that, immediately cut the heat because you know it is working. Then once you know it is working, proceed to the coin setup afterwards.
Title: Re: thioacetamide
Post by: Borek on September 26, 2009, 04:53:53 AM
Just heat it up in water, it should start to stink.

Edit: I have merged topics.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 29, 2009, 09:15:23 PM
well i tryed the thioacetamide to tone my coins but it did not work. but i did come across something that does give me the colors that i want but the colors are very light. heres a picture of a coin that i put in salt water and added current to the water. i guess they call it anodizing. is there anything i can add to my salt water to make the colors stand out more, any info at all would help and i will try what ever you say that migjt help. heres the picture
Title: Re: hydrosulfuric acid
Post by: Borek on September 30, 2009, 03:14:40 AM
Anodizing means using coin as an electrode. If you have just put it into the bath it is not anodizing.
Title: Re: hydrosulfuric acid
Post by: jamesslack on September 30, 2009, 09:35:30 PM
no i put the coin in the salt water then put the + wire on the coin and put the - wire in the salt water and the coin turned with nice colors but they are very light. i was wondering if there was a way makeing the colors brighter some how. with another type of salt or something or some kind of chemical.
Title: Re: hydrosulfuric acid
Post by: renge ishyo on September 30, 2009, 11:44:09 PM
You might want to try heating the discolored coin followed by super quickly cooling it i(probably using dry ice). I know that this is done with certain metals such as titanium to obtain different color patterns, but I don't know if it will work with impure silver. Be sure and try it with a "sacrificial coin" and not a precious one to see how it works  ;)
Title: Re: hydrosulfuric acid
Post by: BluRay on October 01, 2009, 10:35:51 AM
no i put the coin in the salt water then put the + wire on the coin and put the - wire in the salt water and the coin turned with nice colors but they are very light. i was wondering if there was a way makeing the colors brighter some how. with another type of salt or something or some kind of chemical.
You can try with higher voltages or adding some oxidant as hydrogen peroxide, persulphate, ecc., ecc.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 01, 2009, 07:22:54 PM
thanks,   you guys have been alot of help.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 01, 2009, 09:33:27 PM
i will try the dry ice, but will have to fined a way of heating the coin up with out turning it colors by the heat. i think i know a way.
Title: Re: hydrosulfuric acid
Post by: renge ishyo on October 01, 2009, 10:38:59 PM
Let me know how it goes. I was told how to do this with certain metals by a Jewelry maker believe it or not.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 01, 2009, 11:02:31 PM
i will let you know how it works, im getting real close to getting what i want. heres a picture of one with the see threw light colors and dont hide the coin its self.
Title: Re: hydrosulfuric acid
Post by: renge ishyo on October 02, 2009, 12:38:26 AM
That is really close. Now you just need a way to manipulate the color so you can control the pattern.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 02, 2009, 11:57:42 PM
the dry ice did not change the silver color,
Title: Re: hydrosulfuric acid
Post by: renge ishyo on October 03, 2009, 01:28:22 AM
The dry ice in and of itself wouldn't be expected to change the silver color...it is merely a cooling agent so that you can supercool a heated object very quickly by placing it in contact. The heating technique is one way to get metals to display certain colors, but I am no expert on the subject so I will leave it at that. I've been poking around and you may want to check out this book at your local library:

http://www.amazon.com/Coin-Chemistry-Weimar-W-White/dp/0971392498

It apparently has a decent essay on silver toning of coins that might prove useful to you. I'll poke around and see if I can come up with anything else.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 03, 2009, 09:23:17 AM
i did heat the coin frist before putting it on the dry ice to cool it quick. yes the coin chemistry book i have thats why i was wanting to know how you could make h2s gas. but i tryed it too by useing thioacetamide, then tryed a house hold cleaner with black salt to make h2s but it only made my coin black.
Title: Re: hydrosulfuric acid
Post by: BluRay on October 04, 2009, 08:28:55 AM
Sorry, but I haven't understood if you have already tried to heat the discoloured coin in dry conditions in the presence of a little H2S gas (this should produce sulfide layers on the coin).
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 04, 2009, 11:01:09 AM
i tryed to make H2S gas with thioacetamide, heated the thioacetamide up with water added to the  thioacetamide in a test tube with a cap on test tube with a hose running from test tube to another jar that the coin was in. i let the coin set in that jar for 24 hours, i also heated the test tube up intil all the thioacetamide was gone. but it didn't change the silver coin. i also tryed to make H2S gas with black salt and a drain cleaner called the works because it has alot of hydrochloric acid in it. but it made my coin black. the hydrochloric acid pitted the silver. the next thing i want to try is sodium sulfide with another type of acid to make the H2S gas. i need a acid that wont pit the silver when i turn it into a vapor gas.   if you know a acid that i can mix with sodium sulfide to make H2S gas that isn't like hydrochloric acid.   but there aging I'm getting what colors i like with anodizing with different chemicals i found to use with it.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 04, 2009, 11:03:23 AM
same pictures  different angle
Title: Re: hydrosulfuric acid
Post by: BluRay on October 04, 2009, 02:38:49 PM
1. I advise you not to produce H2S with sodium sulphide + an acid: it's very easy to generate enough amount of H2S to kill you...
2. So you haven't heated the coin while the gas was on it; try to do it (it's just a try). Maybe it can work.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 04, 2009, 06:12:11 PM
heating the coin up and putting the H2S gas on it did this.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 04, 2009, 07:12:15 PM
also do you think different type sulfur will give different colors or is sulfur all the same. i know different salts give different colors. now is sodium sulfide a type of salt.
Title: Re: hydrosulfuric acid
Post by: Borek on October 05, 2009, 02:54:47 AM
All sulfur is the same, but each salt is different. Yes, sodium sulfide is a salt.
Title: Re: hydrosulfuric acid
Post by: BluRay on October 05, 2009, 07:33:34 AM
heating the coin up and putting the H2S gas on it did this.

Terrible! However, it does produce sulfide in thin layers... :)
In the beautiful picture of the coin you posted on September 12, 2009, 05:49:08 AM, I noticed that the coin's parts in rilief are more coloured, as if they have been attacked chemically more; for me it's strange that a simple the simple action of a still gas could do it, without other expedient. Maybe they started from a not-perfectly polished coin and then rubbed, or prepared chemically with a solid body the more external part of it before the chemical attack, or the put the coin at a certain angle in a grazing flux of the gas? (I'm asking to all people here).
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 05, 2009, 07:08:15 PM
i have been trying some anodizing, and i have seen that some sodiums give a driffernt color then others. is there a chart that you can look at to see what sodium makes a certain color. i will try the H2S gas agin this weekend and try to control it. but that stuff does stink.
Title: Re: hydrosulfuric acid
Post by: Borek on October 06, 2009, 02:58:52 AM
No idea what you mean by "different sodiums".
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 06, 2009, 06:50:40 AM
type of salts.
Title: Re: hydrosulfuric acid
Post by: Borek on October 06, 2009, 07:40:23 AM
So correctly these have to be named "different salts of sodium". Basically every atom of a given element is identical, regardess of what compound it is found in, but as it is surrounded by other atoms of other elements it may behave a little bit different. Still atom of sodium isolated from sodium glutamate is undistinguishable from atom of sodium isolated from sodium chloride.

Nitpickers will tell you that atoms of element can be different, as they can be different isotopes, but it has nothing to do with compounds in which they are found, so for now we will just ignore it.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 06, 2009, 08:09:27 PM
i might never be able to make coins toned like some of the pro's but i have come along way from all the help here thank you very much. heres one i did today its got all the colors init but it still dont look like the one i was trying to get. but im happy with this one. thank you all
Title: Re: hydrosulfuric acid
Post by: BluRay on October 07, 2009, 06:43:36 AM
And how did you achieve it? It's rather nice. You could even cover part of the coin to colour it only partially.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 07, 2009, 06:37:42 PM
useing low volts and sodium salts, but still buying other tpye of salts to try.
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 08, 2009, 06:52:57 PM
heres what i found out so i dont think i will be able to tone the way i want, read this.The real secret is to buy a diffusion furnace, or maybe two, both a Chemical Vapor Deposition and an Atmospheric. On the CVD furnace one can add a nice uniform layer of polysilicon or nitride to beautifully tone your silver coins. and since you can control, temp, time and pressure you can control your deposition rate and get any spectrum of coloring that is completely natural and undetectable... For those stubborn coppers, we turn to the atmospheric furnace, and grow a slight layer of a high quality oxide at a slow rate, cause one has to remember that a grown oxide consumers its underlying surface as well as growing upwards... Ok, enough of the revealing the biggest trade secrets, 
Title: Re: hydrosulfuric acid
Post by: jamesslack on October 08, 2009, 07:13:38 PM
heres the rest she had to say,     an atmo furnace with Hydrogen or h2 has to be properly mixed with 02 which then results in h20, a wet form of oxide growth which would not look natural and is of a lower quality and grows relatively fast, a dry oxide with heat and o2 and an added solvent such as tca or dce to remove impurities is the way to go Daddy-o, also, an n2 enviroment prior to temp up and growth is critical so one can avoid low quality native oxides, the more sophisticated systems use a pump to pump down the mini enviroment freeing all the area of 02 and creat a rich n2 inert enviroment... But I think I've said too much already...

Title: Re: hydrosulfuric acid
Post by: renge ishyo on October 08, 2009, 07:32:29 PM
I think for your simple setup your result came out just fine  :)

Yeah, to control the exact appearance would take heat and control over the chemical environment. I did not know until I went snooping around that apparently there is a big controversy over toning coins as the coins collectors market used to pay high prices for "naturally toned coins".

This whole thing sort of reminded me of when my dad wanted to imitate the look of ancient Greek artifacts by giving his art sculptures that "green glaze" from exposure to copper metals and whatnot. He even went as far as to bury his sculpture in the backyard for a month in a chemical solution. He got the color he wanted, but it gave a uniform green film over the entire sculpture that looked unnatural. To go beyond that and control when and where the green color appeared on the sculpture would have required a quite complicated setup similar to the one you have just described.