Sciencemadness Discussion Board - Possibility of sulphuric acid?

Possibility of sulphuric acid?

darkflame89 - 19-4-2004 at 02:05

Now i am collecting every single form of making sulphuric acid, and i encountered such a reaction:

5SO2+4H2O+IO3 ---> 5SO4 2- +8(H+)+ I2

Is this possible with sodium chlorate(by heating of bleach..)?

Saerynide - 19-4-2004 at 04:36

I think Im lost.

Where does the iodate come from? NaClO3 isnt even in the equation

Edit: Maybe Im misreading here. Do you mean substituting iodate with chlorate?

[Edited on 19-4-2004 by Saerynide]

BromicAcid - 19-4-2004 at 07:32

It would work but you know how weak bleach is. You mean heating bleach to decompose the hypochlorite to the chloride and the chlorate right? Atleast you would get the double wammy reaction of:

Cl2 + SO2 + 2H2O ---> 2HCl + H2SO4

If you had the solution stirring enough during the reaction to result in the reincorporation of the resultant chlorine gas that is. Personally I like the idea of a stoichiometric quantity of bromine and water efficently stirred with SO2 bubbling through it. As the concentration of H2SO4 rose it would drive off the HBr somewhat pure with the exception of bromine vapor and some water vapor and residual SO2 and in the end you might end up with near pure H2SO4.

darkflame89 - 20-4-2004 at 01:00

Wait wait, i saw the reaction as the process to isolate iodine from the sodium iodate found in Chile. The precipitate of iodine and the sulphate ions plus the high number of hydrogen ions generated attracted my attention. I thought what a great way to generate the acid, and thought of whether i could sodium chlorate(V).

Anyway about the Cl2 gas forming both sulphuric acid and hydrochloric acid, i jus so happy about it. NVM about the in purity, the double mixture of strong acids might even act like aqua regia!!

Saerynide - 20-4-2004 at 01:30

But we still have to find SO2

darkflame89 - 20-4-2004 at 02:29

That is why i am also considering certain reactions that give out this gas. I am considering of using photographer hypo, but i am still looking for it...

S + O

axehandle - 20-4-2004 at 06:13

I hate to point out the obvious (well, I actually like it

), but burning sulfur gives SO2 in hellish quantities. Take my word for it.

Saerynide - 20-4-2004 at 07:16

We dont have access to sulfur

thunderfvck - 20-4-2004 at 08:10

Not even at the pharmacies? I'm sure you've already looked, but that's where I found mine. It's used for acne. I got a nice big bottle of it.

Saerynide - 20-4-2004 at 09:33

Nope, zippo. Its probably regulated or some shit like that

Btw, wow, sulfur in pharmacies?

Edit:
Look at this from the Merck Index on Al Sulfate:

"On long boiling of aq soln, insol basic salt ppts. The soln is acid."

How does that work? So by boiling it slowly, you get H2SO4 and Al(OH)3??

[Edited on 20-4-2004 by Saerynide]

The_Davster - 20-4-2004 at 14:18

Quote:

Originally posted by thunderfvck
Not even at the pharmacies? I'm sure you've already looked, but that's where I found mine. It's used for acne. I got a nice big bottle of it.

What chain of pharmacies was this from? I'm over to your west in Alberta. Most of the pharmacies here dont carry anything good. The best thing I have found in a pharmacy here is oxalic acid. I dont really need any more sulfur, I have 500g I bought from a local supplier but its interesting to know other sources.

BromicAcid - 20-4-2004 at 18:07

You could always roast a sulfide. You could always get those through some rock collecting connections, in that way elemental sulfur could be procured too. If you were really desperate you could extract it from match heads but it's a pain and as most people's luck would go if you went into a store and bought 5 boxes of matches they are going to think that you are making drugs around my house, not that you are just innocently extracting the sulfur (and the chlorate and everything else). If you were just looking for straight SO2 though you could get it from the same source as me. I bought a few lithium/sulfur dioxide batteries on eBay awhile back. When I need SO2 I drill a hole in one side and drop into a jar and cap with a stopper with a glass tube leading out. It's liquid SO2 on the inside and each battery has about 20 g or so but on the even better side, after it's all done I take out the battery and cut a circle around it with a hack saw, about 5 g of lithium sheet on the inside

Edit:

Also, don't forget that it is avalible from agricultural sources.

[Edited on 4/21/2004 by BromicAcid]

darkflame89 - 21-4-2004 at 02:30

Saerynide: That is what I suggested last time in your posts in the MgSO4 to H2SO4. Aluminium sulphate actually hydrolyses to form the products you stated; its an acidic salt. Once you remove your aluminium hydroxide, you will end up with sulphuric acid. I am looking into iron sulphates too for this matter. Aluminium electrodes are dirt cheap.

Look at this:http://phys4.harvard.edu/~wilson/arsenic/countries/bangladesh/mortoza/ARTICLE5.html

thunderfvck:No, sulphur is not found is pharmacies. I have combed it entirely, all that is useful is, hydrogen peroxide, potassium citrate, epsom salts, alcohol, povidone alcohol, aspirin as stuff like that. But there is just no freaking trace of sulphur!!! :mad:

I mean if me and Saerynide could find sulphur and potassium nitrate, i would long set up a mini sulphur burning plant like axehandle.

Sigh, so now we are improvising all we can from OTC materials..

BromicAcid: As for sulfide, there's not really a hope too. You might have heard that Singapore has no natural resources, not less to say rock collecting! As for ebay, that's not really a choice as my budget is quite limited, and remember, i am only 15. and no, you can't find it in agriculture stuff. there are not really any farms here..and fertilisers contains a whole lot of other shit inside..

[Edited on 21-4-2004 by darkflame89]

darkflame89 - 21-4-2004 at 02:38

And, BromicAcid, bromine gas is not feasible because, this acid will turn sulphuric acid back to sulphur dioxide and bromine. Hydroiodic acid is not feasible too, it will react to reduce it to hydrogen sulphide gas and iodine.

Saerynide - 21-4-2004 at 05:21

I still dont understand why the sulfuric acid doesnt react back with the aluminum hydroxide

Al Koholic - 21-4-2004 at 06:29

A good source of sulphur is as was already mentioned, MgSO4, Na2SO4, CaSO4, etc. These compounds (I don't know if Al2(SO4)3 would work here...) can just be heated with charcoal (I mean HEATED) and you will end up with an impure melt of the metal sulphides.

HCl is dropped on this in a gas generator (Kipp generator works best) and you bubble the H2S through an oxidizing solution like H2O2 to precipitate the S.

Cheap, dirty, bad smelling, yes. Difficult to find the chems, difficult procedure, risk of dying if you do it outside, no.

DDTea - 21-4-2004 at 07:00

Has anyone considered making Sulfuric Acid from Onions? As you know, Onions contain propanethiol S-oxide, an upwardly mobile gas that is released when you break the Onions' cells, i.e.: cutting, biting into it, or whatever. In contact with water, it forms Sulfuric Acid, and this is why it makes you cry.

So, what if you were to put a few Onions in a blender, along with some warm water, and then thoroughly frappe it

. From there, you could separate the dilute acid by filtration, or maybe distillation. It would be purified by boiling.

This would be a very strange method, no doubt, but it might be worth a try--because ANYONE can get onions

Saerynide - 21-4-2004 at 07:10

Hmmm.. Thats really interesting, but it would require like 5 tons of onions to get a bit of 98% H2SO4

Darkflame, I read the article, but it says:

"The hydrogen ions released combine with alkalinity anions (HCO3-, CO32-, and OH-) to produce carbon dioxide and water and lower the pH (Boyd, 1979). Provided that the pH can be controlled by adding sufficient cations (in the form of lime slurry in water treatment practice), the hydroxide remains as a colloidal solid, and acts as a filter for particulate matter in the raw water supply. However, if the pH drops to around 5 or less, the hydroxide redissolves, producing a clear extremely acidic solution"

Its going to be really impractical to keep the pH above 5 cause we'll need TONS of water, and that would mean TONS of boiling just to get a small amount of acid

Edit: That was the most disorganized paper I have ever read. I can't believe someone at Harvard wrote that

[Edited on 21-4-2004 by Saerynide]

BromicAcid - 21-4-2004 at 08:09

Quote:

And, BromicAcid, bromine gas is not feasible because, this acid will turn sulphuric acid back to sulphur dioxide and bromine. Hydroiodic acid is not feasible too, it will react to reduce it to hydrogen sulphide gas and iodine.

I've read that industrially exit gasses from the production of HBr are treated with small amounts of SO2 to convert unreacted bromine to HBr. I got that from "Bromine and its Compounds" however I don't know if this is still the case of if it works in concentrated medium. I will agree with you on the HI reacting back and reducing the H2SO4 though.

blip - 21-4-2004 at 14:47

I have this cat and dog shampoo that contains sulfur. I don't know where its from or how it was purchased because I didn't buy it. Anyway on the front there's this purple rectangle with white text saying SebaLyt in large letters but rotated counter-clockwise. Another thing it says there is "NDC 47203-350-08". To the right of that rectangle it says "Shampoo", gives three ingredients, then "All Purpose Antiseborrheic Antibacterial Cleansing Formulation for Cats and Dogs." Also on the back "Active Ingredients: Sulfur 2%, Salicylic Acid 2% and Triclosan 0.5%.", then it gives a product description, indications, directions for use, and precautions. From searching on Google, apparently no prescription is required.

I put the entire contents in a kitty litter bucket nearly full of water being careful many suds don't form. It seems so far that the sulfur is still in the undissolved stuff but I haven't done anything like decanting and adding more water to dissolve the green stuff so that the sulfur comes out.

thunderfvck - 21-4-2004 at 16:16

It's at Pharmaprix. Bottle reads:

Atlas (producer, labratoire Atlas inc., montreal, Quebec, blah) 125 g.

Sulphur
USP
antiseptic for acne

(fire sign)
flammable

Indication: Parasiticide and antiseptic for acne and superficial skin conditions.

Directions: Prepare an ointment with one part sulfur (funny how they change the way they spell it) and ten parts petrolleum jelly. Apply liberally to affected areas. Avoid contact with eyes.

It's a yellow powder. I assume it's of good purity (USP). I found it right next to the citric acid, near the glycerin, the oil of wintergreen, the witches hazzle (or whatever), etc. It's a shame you guys don't get it. I paid about $5 for it I believe, is this a good deal or what? Should I stock up?

I think I'm going to go burn some sulfur now.

[Edited on 22-4-2004 by thunderfvck]

darkflame89 - 22-4-2004 at 03:17

Ok about the sulphur in pharmacy i will look again. About the onions, i read that in the article at about.com. Sounds promising but we might need tons of onions. About the aluminium sulphate, that isn't so bad. Ok what you need is to test the waters to see if it has reached pH 5 or not. Then you can pour out the H2SO4 and clear out the aluminium hydroxide. And put in some more new materials. This can go on, i dunno about this plan, might or might not work. I will have to wait until after the exams to try.

But the equation looks somthing like this:

Al2(SO4)3 + H20 <----> H2SO4 + Al(OH)3

The equilibrum occurs when the pH is about 5. So if you clear out the precipitate, you can cause the the reaction to happen towards the right, forming more sulphuric acid.

Pyrovus - 22-4-2004 at 03:52

On the Al2(SO4)3 front, perhaps an easier route may be to use H3PO4. AlPO4 is extremely insoluble, so the following reaction should occur:
Al2(SO4)3 + 2H3PO4 -> 2AlPO4 + 3H2SO4
And as H3PO4 is a fairly decent acid, the conjugate base PO4[3-] should show less tendency to back-react to reform H3PO4.

darkflame89 - 23-4-2004 at 04:46

Phosphoric acid? Of course, what's more is so powerful! Its the only strong acid i can find around, sold as anti-rust

darkflame89 - 26-4-2004 at 01:49

Recently found this equation :

SO2Cl2 + 2H20 --> H2SO4 + 2HCl

So what is that SO2Cl2 compund? Is it dangerous? Looks dangerous to me..

Edit: Found more info about this compound called sulphuryl chloride

General
Synonyms: sulfonyl chloride, sulphuric oxychloride, chlorosulphuric acid
Molecular formula: Cl2O2S
CAS No: 7791-25-5
EINECS No: 232-245-6
Physical data
Appearance: colourless or pale yellow liquid
Melting point: -54 C
Boiling point: 68-70 C
Vapour density: 4.7
Vapour pressure: 105 mm Hg at 20 C
Density (g cm-3): 1.68
Flash point: none
Explosion limits:
Autoignition temperature:

Stability
Reacts violently with water. Incompatible with acids, alcohols, bases, metals, amines, moisture.

Toxicology
Highly toxic. May be fatal if inhaled, swallowed or absorbed through skin. Corrosive - causes burns. Lachrymator. Very destructive of mucous membranes.
Toxicity data
(The meaning of any toxicological abbreviations which appear in this section is given here.)
IHL-RAT LC50 131 ppm (male), 242 ppm (female)

Risk phrases
(The meaning of any risk phrases which appear in this section is given here.)
R14 R23 R24 R25 R34 R37.

[Edited on 26-4-2004 by darkflame89]

Saerynide - 26-4-2004 at 04:00

Eeeee... Im not touching that

No H2SO4 is better than no life!

BromicAcid - 26-4-2004 at 06:03

Quote:

SO2Cl2 + 2H20 --> H2SO4 + 2HCl

Sulphuryl chloride can be made by reacting SO2 with Cl2 over activated charcoal or something of that extent. When mixed with water it is the identical overall reaction as when you bubble SO2 though water with Cl2. The overall effect in both cases is the Cl2 oxidizes the SO2. SO2Cl2 might even be an intermediate in the reactionary scheme of things.

I also saw a reaction over at physicsforums that thunderfvck mentioned:

3H2SO3 --@150C--> 2H2SO4 + S + H2O

It was just interesting in that I had never saw it before.

Edit: Went to the library and saw some interesting information. Here is just a spiel of it. Electrolysis of monohydrated sulfur trioxide, aka 100% H2SO4 can be accomidated to facilitate just the electroysis of water overall leading to oleum solutions. The decomposition point of ferrous sulfate can be reduced by the addition of a small amount of magnesium sulfate and small amounts of sand for furnishing SO3. Reduction of calcium sulfate with carbon in stoichiometric amounts leads to the formation of CO2/CO/SO2 with SO2 being almost quantitive. Sulfuric acid is formed by the action of oxidizing agents on the polythionic acids and on the thiosulfates. F.P. van Denberg made SO3 by the electrolysis of molten CaSO4!

[Edited on 4/26/2004 by BromicAcid]

darkflame89 - 27-4-2004 at 01:33

Good info there, very useful...

i will just go and look up some more..

axehandle - 27-4-2004 at 04:58

Is it really worth killing yourself just to get hold of H2SO4?

darkflame89 - 28-4-2004 at 03:12

Nope, i am just looking for all possible different ways to make H2SO4. As the processes are small scale at home, i will have to combine several processes at once to get the most out of it.

darkflame89 - 1-5-2004 at 00:57

Going back to the earlier point about adding phosphuric acid to aluminium sulphate to get sulphuric acid, can the same be done to magnesium phosphate? That is, how soluble is magnesium phosphate in water?

thunderfvck - 1-5-2004 at 01:09

www.chemfinder.com

magnesium phosphate, water solubility = 0.005 mg/ml

Just my 2 Euro after a nasty incident

axehandle - 1-5-2004 at 01:28

Gypsym calcium sulfate decomposed into SO2 at 900-ish degrees C. This could probably be harnessed and passed over a Fe2O3 catalyst, instead of deposited in my lungs.

darkflame89 - 2-5-2004 at 00:38

900 degrees!!??

This not feasible here, my parents will be freaked out..

BromicAcid - 2-5-2004 at 07:28

Just make one of those at home carbon arc furnaces that I see in the older chemistry books. They have no outside indication that they operate at ludicrously high temperatures. Take a magnesium based pot and drill two holes across from each other and insert graphite electrodes. Place them so they are not very far apart and cement them in place. Run one wire directly to a wall socket and take the other and put a lead sinker on it. Take another wire and put a lead sinker on that and run that one to the wall. Now take a pyrex deep dish and fill it with a saturated NaCl solution. By varying the distance between the sinkers in the bowl you vary the power to the arc furnace. Mind you I have never attempted this but the old chemistry book I saw claimed nails could be easily melted so decomposing CaSO4 should be a snap!

axehandle - 2-5-2004 at 07:33

Good suggestion. A more expensive but perhaps more efficient way would be to use tungsten electrodes, about 10mm apart, and create a static plasma arc between them using an NST. That's actually something I plan to build soon: A plasma arc melting oven. No more carrying around huge heavy dangerous propane tanks. Must find a better refractory mix though, and the W electrodes won't be easy to find. Hmm, aren't they used in plasma arc spot welding....?

[Edited on 2004-5-2 by axehandle]

chemoleo - 2-5-2004 at 09:02

On the note of electric arcs - it is actually quite easy to do, at least on a small scale.
The main restriction is a massive transformer.
Then pretty much go ahead as bromic described. I had a 120A/42V transformer, a massive fire cement block with the chamber in the middle, and two holes for the electrodes.
Always WEAR THICK sunglasses when doing this, the light is extremely bright, like a 500W halogen light reduced to a single small spot.
Anyway, I got the fire cement melted to a thin liquid within few seconds - even though it was 2-3 cm away from the actual arc!
Needless to say, I made some calcium carbide this way... within a few seconds.

Organikum - 2-5-2004 at 10:04

You dont need an transformer. A saltwater rheostat will suffice and works well.

A transformer is technically wrong anyways - you want a ballast for arc furnaces as the problem of arcs is that as soon the arc strucks the resistance drops to near zero and this will blow any fuse. Same as with HID lamps.

Uiiii, now we found the problem with your big transformer chemoleo! The problem is:
ABUSE

chemoleo - 2-5-2004 at 12:31

Isn't 'abuse' the point of being a mad scientist?

- the transformer was never meant to be used for melting fire cement.

I don't understand the point of your post though

-what is the problem with my transformer? The problem I mentioned in the 'massive transformer ' thread is of a completely different nature?!?

darkflame89 - 3-5-2004 at 02:21

As transformers are not found in Singapore can I make them myself, i plan on doing one anyway as a holiday project. I have been reading up on this and do think this is feasible? I know you all get your transformers really easy, but here.. sigh. Sometimes i regret a bit as to how Singapore was shaped..

Anyways, the electric arc method is good. I will implement it to create a mini melting furnace.

MOT?

axehandle - 3-5-2004 at 05:16

Are also microwave ovens not found in Singapore? They all contain something called an MOT (Microwave Oven Transformer), which can put out one hell of a current.

Btw, you'll need tungsten or graphite electrodes, and an inert protection gas. Nitrogen or argon is fine.

[Edited on 2004-5-3 by axehandle]

chemoleo - 3-5-2004 at 08:11

LOL - you are telling me that transformers are not used in Singapore??? I guess you don't use electricity there... now that explains it!

darkflame89 - 4-5-2004 at 02:32

WE do use transformers, is just that i am a amateur, i do not know the in and outs of all electrical equipment, and my movements are limited by my parents

edit: I found this!: http://www.popsci.com/popsci/science/article/0,12543,611070,...

[Edited on 4-5-2004 by darkflame89]

darkflame89 - 7-5-2004 at 02:43

What is saltwarer rheostat? I mean it just boils the salt water solution, doesn't it? How high temp. can it reach?

edit: sorry did not read too properly, i having a Biology test tomorrow. So, the salt water rheostat is used to regulate the current for the arc method described.

[Edited on 7-5-2004 by darkflame89]

axehandle - 7-5-2004 at 03:07

A salt water rheostat is a variable resistor consisting of two electrodes submerged in salt water. The resistance increases in proportion to the electrode interdistance. I think the brine will get quite hot and boil, I've never tried this myself, but boiled-off water should be possible to replace easily by adding tap water.

But be careful, OK? I don't mean to flame, but you don't seem to have much experience with electronics, and wall outlet AC can kill you of you treat it with disrespect.

PS: "brine" == "saturated NaCl(aq) solution"

[Edited on 2004-5-7 by axehandle]

darkflame89 - 8-5-2004 at 00:00

Yah, i understand that.. I don't know much about stuff like this..sigh..i need a full course on elctrical stuff..

Of course i will not plug straight to the wall plug w/o prior knowledge,

[Edited on 8-5-2004 by darkflame89]

acx01b - 8-5-2004 at 09:00

lol
so many wrong things i saw..

sorry but h3po4 is not a strong acid

the reactions to make h2so4 from so2:
you need a catalyst (v2o5) and high temperatures to make concentrated acid (dried acid, 100%),
you cannot make concentrated acid from so2 + i2 + h2o
you cannot make concentrated acid from h2s + i2 + h2o
you cannot make concentrated acid from so2 + io3 + h2o

you can make something ph = 1 but not less.

axehandle - 10-5-2004 at 13:18

Quote:

lol
so many wrong things i saw..

sorry but h3po4 is not a strong acid

the reactions to make h2so4 from so2:
you need a catalyst (v2o5) and high temperatures to make concentrated acid (dried acid, 100%),
you cannot make concentrated acid from so2 + i2 + h2o
you cannot make concentrated acid from h2s + i2 + h2o
you cannot make concentrated acid from so2 + io3 + h2o

you can make something ph = 1 but not less.

Ouch, my eyes! Please capitalize properly. Your point may be valid, but something like "i2" just sticks needles into everyones eyes....

darkflame89 - 11-5-2004 at 00:23

The resultant acid might not be concentrated, but you can always concentrate it by various ways like electrolysis.

acx01b - 11-5-2004 at 04:15

from acid ph=0.5 or something u got ph=0 ?

and from h2so4.10 h2o you can get dried or 1h2o h2so4 ???

plleaseeeeeeeeeeeeeee explain more

graphite electrodes? (i have :-)

darkflame89 - 12-5-2004 at 02:21

Yup, using graphite electrodes, stick them into the acid, connect to battery and water will leave the system as hydrogen gas and oxygen gas. Keep the entire setup under low humidity, you wouldn't want the acid to suck water form air do you?

I study this in my chemistry lessons, so i am quite sure of this.

frogfot - 13-5-2004 at 14:10

Someone was talking about burning S to get SO2? How would one solve the problem with evaporating S? I mean, making some "afterburner" is not an option for an amateur..

Wouldn't "lead chamber process" (KNO3+S) give same problem?

It seems that using NO2 as oxygen transporter for SO2-->SO3 is promicing. Just letting SO2/air/little ammount of NOx go through a long pipe.. This would be sure simpler than heating a catalyst to do the same job...

what about single replacement?

sanity gone - 13-5-2004 at 20:33

I was thinking it might be possible to replace a sulpahate compound with single replacement and filter out the metal and what not.

[Edited on 14-5-2004 by sanity gone]

Tish tish.

axehandle - 13-5-2004 at 20:42

Quote:

Someone was talking about burning S to get SO2? How would one solve the problem with evaporating S? I mean, making some "afterburner" is not an option for an amateur..

That depends on the amateur.

frogfot - 13-5-2004 at 22:45

Yeah, but welding is most probably required..

Btw, what about electrolysis of CuSO4

:

CuSO4 + H2O --> H2SO4 + Cu

darkflame89 - 14-5-2004 at 02:21

Ya i considered the electrolysis of CuSO4 too. While it is feasible, i need to make the CuSO4 by electrolysis too as it is not sold here. Frogfot's idea about the NOx gases are good, what heppens to the NOx anyway? You see, i am trying to build a crude version of the birkeland-eyde reactor of the synthesis of NOx gases so that nitric acid can be made.

About the burning of S, i am still thinking how to go about it, for one, i have very little experience on such things, two, I am looking at how axehandle's project go and so hoping to learn something.

axehandle - 14-5-2004 at 06:13

Quote:

Ya i considered the electrolysis of CuSO4 too. While it is feasible, i need to make the CuSO4 by electrolysis too as it is not sold here. Frogfot's idea about the NOx gases

All pottery suppliers should have it. It's a very common glaze colour.

Quote:

are good, what heppens to the NOx anyway? You see, i am trying to build a

In H2SO4 production? Recycled in Gay-Lussac (or was it Glover?) towers. Google for "lead chamber process".

Basically, the NO2 acts as a catalyst like this:
SO2 + NO2 --> SO3 + NO
NO +1/2O2 --> NO2

Quote:

crude version of the birkeland-eyde reactor of the synthesis of NOx gases so that nitric acid can be made.

About the burning of S, i am still thinking how to go about it, for one, i have very little experience on such things, two, I am looking at how axehandle's project go and so hoping to learn something.

So am I, so am I. I think my new furnace will need about a week to dry out completely, then it's casting time. A week on hold is also good for my hand to have a chance to heal -- and besides, casting aluminium while on morphine is probably a bad idea

.

[Edited on 2004-5-14 by axehandle]

frogfot - 14-5-2004 at 06:46

Whow, that Birkeland-Eyde reactor thread is a nice read!

As for SO2 source, it would be really nice to get some Na2SO3 ...mmm, wish it was sold in usual stores.. Then one could "spice" it with enough nitrite so that on addition on say HCl or battery H2SO4 one would get SO2 with known ammount of NOx. Smaller concentrations would basically require a long "reaction pipe". (One thing I'm not sure about is, if it's ok to add a nitrite to Na2SO3 soln.. I mean if theres any sidereactions)

Axehandle I have trouble to find a good airpump that does not make much noise.. Currently I use one of those car tier compressors (running at 9V instead of 12V).. Though that thing is cheap, it's very loud..

I seen you're using aquarium pump, but doesn't those heat up alot?

axehandle - 14-5-2004 at 08:00

Quote:

Axehandle I have trouble to find a good airpump that does not make much noise.. Currently I use one of those car tier compressors (running at 9V instead of 12V).. Though that thing is cheap, it's very loud..
I seen you're using aquarium pump, but doesn't those heat up alot?

Not that I've noticed. But I use the kind that are good down to a water depth of 2..3 meters, which is overkill for this application. They are virtually silent. A bit too expensive as well, unfortunately. I've been thinking of constructing a cylinder-piston pump with a small electrical motor, but I don't think I'll be able to without a lathe. The aquarium pumps at least work, and are silent.

Edit: 3 of those damned things cost me about 1200 SEK....

[Edited on 2004-5-14 by axehandle]

frogfot - 14-5-2004 at 11:13

Whow, 400kr (50$).. thats like price of a big garden pump..

Anyway, I have tryed to solve the noise problem by covering my pump with a 30l bucket. Noise is greately reduced, and there is enough of air to cool the motor. Mine cost 13$ (huh and it can give like 18atm.. but thats another thing)

Duh, I wanna correct my last post..
I just found out that SO3 contacting with water is a "no no", since this'll form a fog that is very hard to settle down. Thats why it's not adviseable to ubtain SO2 mix from aqueous Na2SO3/nitrite mix..
Better way would be to make all gases separately, dry them over CaCl2, and only then the SO2, NOx and air would be mixed and transported through a long pipe (copper pipe would do here, or?)
Huh, I'm more and more interested in this synth..

Btw, in industry they use 98% H2SO4 to absorb SO3. Would 95% do? ..difference is not big, but I'm not experienced in this..

[Edited on 14-5-2004 by frogfot]

axehandle - 15-5-2004 at 01:56

Where did you get that pump? It sounds interesting if it can be "silenced".

Cu piping should be fine if it's dry air/SO2 mix, as far as I've been able to determine. It might get eaten trough in a year or something, though.

I haven't really solved the catch-22 problem when it comes to the absorption yet. I am going to try direct contact between the water surface and the generated SO3. It should stay put in the water as H2SO4 then, I'd _think_. Worst case: I'll take a small trip to Denmark and buy a liter of H2SO4.

frogfot - 15-5-2004 at 03:18

Try www.jula.se or www.biltema.se (art. nr. 15-980), both sell same thing, but first store sell it cheaper.. (for some reason first adress doesn't work.. but it will.. someday..

)
Thay got also small silent (58db) air compressor but it's more expencive..

As for absorbtion of SO3, I thoat to assemble my 25 cm long fractionating column that will have a dropping funnel with H2SO4.. All this will be in glass, I basically got all equipement.. but that experiment is just in theory untill I find source of Na2SO3..

Wondering if theres an accurate way to calculate lead content in car battery acid? We basically got some dissolved PbSO4 and Pb(HSO4)2. The problem with calculations is that solubility of the first salt decreases with cons of H2SO4, but it's the opposite for the second salt..
Wish there was an easier way to check Pb content (not using EDTA..)

darkflame89 - 15-5-2004 at 05:06

I know that that SO3 gas in contact with water is a very bad idea, but how do you absorb it with sulphuric acid when you do not have any sulphuric acid, and that is the purpose why i am going to such lengths to "manufacture acids" at home..

Good point

axehandle - 15-5-2004 at 05:43

Quote:

I know that that SO3 gas in contact with water is a very bad idea, but how do you absorb it with sulphuric acid when you do not have any sulphuric acid, and that is the purpose why i am going to such lengths to "manufacture acids" at home..

That, mate, is my catch-22 situation. A lead-chember-like absorption thingie could probably be used during the first run, after that (when I have a litre or two of H2SO4), I can use the industry standard: Let is absorb in 98% H2SO4, add water as needed during the process.

frogfot - 15-5-2004 at 10:18

Huh, I can boil down the battery acid to get approx. 95%, I've tested this already. But this procidure is a bit dangerous, so I wanna avoid it totally (well, boiling H2SO4 is probably more dangerous than handling oleum)
Thats why I was asking couple of posts above if it's ok to use 95% instead of 98% in SO3 absorbtion..

Oh, I didn't know what was catch 22

Didn't lead chamber gave only up to 70%? maby I'm wrong..

EDIT: Oh, just wanned to point out that oleum can be only diluted with 50% H2SO4, I heard it exploded on contact with just water..

[Edited on 15-5-2004 by frogfot]

[Edited on 15-5-2004 by frogfot]

some different tacks

S.C. Wack - 15-5-2004 at 15:02

A pair of Swiss chemists were granted a pair of interesting patents: GB618548 and US2531137. Usually when one thinks HCl, NaCl, H2SO4, the HCl is being produced. In the GB patent this runs backwards: Na2SO4 + HCl = NaCl + H2SO4. The US patent is Cl2 + SO2 + Na2SO4 + H2O = 2H2SO4 + NaCl. The first reaction is practical if it works. I would not be posting patents that required pressure, vacuum, etc.

As for the ferrous sulfate, oxidation to ferric is not a problem, according to Mellor. He says that heating FeSO4.H2O proceeds through the ferric intermediate.The very first prep mentioned of SO3 by him is: Fe2(SO4)3 + distill = Fe2O3 + 3SO3. He also illustrates a nifty apparatus for lab prep of SO3 or H2SO4 from SO2/air. He says that the yields using Fe2O3(instead of V2O5 or Pt) as catalyst are 60%.

The CRC gives the "temperature of energetic decomposition" to SO3:
PbSO4 - 705
CuSO4 - 670
This may still take a long time though. This may be a way around the crap that is in the "93% H2SO4" of the hardware stores, if the salts you make from it can be crystallized nicely.

I've seen patents that state that when ammonium sulfate is heated in H2SO4, ammonium bisulfate and and NH3 are released. However, WO03027018, says that if ammonium sulfate and H2SO4 are heated to pretty much exactly 280C, ammonia and more sulfuric acid are the products. If the bisulfate is the actual or by-product, he does not say so.

Patents are often wrong or misleading, and espacenet itself is unreliable. One day it will tell you there is no such patent, the next day it will show the patent, and the next day you may be unable to access the site at all.

Mentioned before but worth repeating: 2NaHSO4 + 400C = Na2S2O7. Na2S2O7 + H2SO4 + heat = 2NaHSO4 + SO3. This could be a way around crap H2SO4, converting it to SO3. No, SO3 does not explode on contact with water. Hot, loud, fuming, yes, explosive no.

BromicAcid - 25-5-2004 at 14:37

Quote:

Now i am collecting every single form of making sulphuric acid

This just crossed my mind today although I have never done this so it is just specualtion.

CuSO4 (aq) + HCCH (g) ----> H2SO4 (aq) + CuC2 (s)

Being that copper acetylide is somewhat insoluble. However I don't know how readily it forms or how well it deals with concentrated acid or even how available copper sulfate is in countries where sulfuric acid is commercially unavalible. However copper sulfate is avalible here and MAPP gas is too, which contains a decent % of C2H2 but it doesn't matter as H2SO4 is OTC here.

Edit: Yes I knew copper acetylide was explosive but that is what made this method so mad, however it appears from my initial searching that this compound only forms in the presence of ammonia or under basic conditions, in either of those two circumstances any H2SO4 formed would be immediately consumed and therefore this method now appears to be a flop

(I tried, oh well...)

[Edited on 5/26/2004 by BromicAcid]

CuSO4 production

sanity gone - 26-5-2004 at 22:55

The way I got my CuSO4 was by the electrolysis of MgSO4 (commonly sold as Epsom Salts) with copper electrodes. What I did was make a highly saturated solution and used the temprature method to crystalize CuSO4. If I find time I'll go down to the lab and try this.
Note: The electrolysis of MgSO4 also makes really dilute H2SO4.
Also, if you want elemental sulfur I think it is done by:
Na2S + KIO3-->S + I- + KOH, but I'm not 100% sure.

darkflame89 - 28-5-2004 at 04:45

I know, i know, i have done that before. Regarding the production of sulfur, that's a little tricky, there is generally no such sources of sulfide

new idea for sulfur

sanity gone - 29-5-2004 at 10:37

I was doing some research and thought I'd pass a different idea along:
Fools Gold (pyrite) is FeS. An old method for sulfuric acid production was roasting pyrite (I think it happens around 150C).

4 FeS + 7 O2--> 2 Fe2O3 + 4 SO2(g)

2SO2+O2-->2SO3

SO3+H20--->H2SO4

So, in theroy... 20g of pyrite could yeild 4.55M H2SO4 in 50mL of H2O (I think my math holds up, but haven't double checked).

[Edited on 29-5-2004 by sanity gone]

[Edited on 30-5-2004 by sanity gone]

darkflame89 - 30-5-2004 at 05:34

Ah..good idea there, but I don't think there's pyrite round here in Singapore. But I will scoot around and see. Also, you can add hydrochloric acid to the sulfide, and hydrogen sulfide gas will be given off..

Chemtastic - 22-6-2004 at 20:26

I used to collect rocks, and I bought a sample of sulfur (I'd say about a mole of it) for $3. It seems reasonably pure, and if it has any contaminants, I would think only the sulfur could be readily oxidized by atmospheric O2.

So, S + O2 --> SO2

And SO3 + H2O --> H2SO4.

Wouldn't the most convenient method be to find a reaction for the conversion of sulfur dioxide to sulfur trioxide?

Theoretic - 23-6-2004 at 00:09

Nitrite and sulfite in aqueous solution don't give side reactions, they give hydroxylammonium derivatives in full yield, that are then hydrolysed to hydroxylamine...

chemoleo - 23-6-2004 at 11:53

sanity gone/chemtastic -
pyrite is FeS2 to my knowledge. It doesn't react with HCl, while FeS does (producing H2S, smelly).
Nonetheless... if you read around the forum a little bit, you will find that SO2 oxidation is not quite as simple as it sounds- I suggest you read some of axehandles threads. It requires high temps, catalyst, and a decent flow of SO2. Other than doing the FeS2 roasting on an industrial scale, I don't see much chance on doing it at home!

sanity gone - 23-6-2004 at 14:29

Well I *think* FeS2 can be oxidized by the reaction of:
4FeS2 + 15O2 + 14H2O --> 4Fe(OH)3 + 8H2SO4

Jome - 23-6-2004 at 14:55

When adding oxalic acid to saturated CuSO4 solution insoluble copper-oxalate is formed, and sulfuric acid is released. The reaction is probably a equilibrium, Cu+2 SO4-2 + (COOH)2 ----> Cu(COO)2 + H2SO4.

Perhaps this dilute acid could be made more concentrated if Cu(COO)2 is removed and more CuSO4 and oxalic is added?
Anyone with access to accurate indicators who can measure the pH of the equlilibrium?

blip - 23-6-2004 at 15:48

If you can make SO2 in generous quantities but not a decent flow, maybe you could sacrifice some of your beloved NaOH to be near the source and convert it to Na2SO3. As I haven't tried it though, I don't know whether it needs to be in solution with the gas bubbled through or if it can remain as a solid, or even if both would work equally well. When you feel that you're ready for the flow, fire up your catalyst and pour on your sufficiently strong acid of choice slowly enough.

darkflame89 - 24-6-2004 at 02:35

Quote:

When adding oxalic acid to saturated CuSO4 solution insoluble copper-oxalate is formed, and sulfuric acid is released. The reaction is probably a equilibrium, Cu+2 SO4-2 + (COOH)2 ----> Cu(COO)2 + H2SO4.

well, that is roughly the same of what i am trying to do; add phosphoric acid to MgSO4. The ppt magnesium phosphate can be filtered, leaving behind sulphuric acid.

Jome - 29-6-2004 at 15:09

If a flow of SO2 is created somehow, why not bubble it into H2O2-solution to get H2SO4 instantly instead of using a catalyst to turn it into SO3 and then absorbing this into water? :cool:

Or, you could electrolyse copper out of a saturated solution of copper-sulfate, and then boil this ~1,38M sulfuric acid down until its concentrated.... The advantage of using copper instead of magnesium sulfate is that copper doesent spontaneusly (sp?) react back with the acid, therefore no salt-bridge is necessary.

Cyrus - 20-3-2005 at 22:35

Ahh, arc furnaces.

Organikum, I'm just an electronics newbie, but I thought that transformers would help the efficiency of the arc; an arc draws 20 volts (from 120 volt wall socket, say), say, so the other 100 volts are wasted. If the wall socket can take only 15 amps, then the power used by the arc (VA IIRC) would be 300 "W", right? Now if the transformer transforms from 120 volts to 60 volts, then the arc still takes 20 volts, but it can draw 30 amps, right? That means the arc gets 600 "W". Now w/ the transformer the current draw will fluctuate more w/ a given amount of variation in the distance of the electrodes (which corresponds with the voltage drop across them) but that's ok to a certain extent, but if the transformer went all the way down to, say, 20 volts, then the fluctuation in current would be bad. Don't ask me to explain this one.

For ballast I plan to use an inductor, and shunts on the transformer. Please correct me (in reasonably simple terminology) if I"m wrong.

Lesse, I also want to use a rectifier to get DC going to the arc- it's more efficient, and only one electrode erodes significantly, meaning that the distance between the electrodes can be adjusted with a simple motor and zener diode setup. As the electrodes erode and get farther apart, the voltage across them increases, letting current though the zener diode and the motor.... I hope.

As for insulation- I was planning on using kaowool (ceramic insulation blanket) for the outer layer but I think I'll save that for a new furnace. So the refractory would be a layer of clay-based stuff (perhaps paperclay, which apparently has almost no shrinkage from when it's wet to when it's fired, meaning that it won't crack as much.) and then on the inside I'm planning to use a mix of 95% zircon and 5% kaolin (clay stuff). I'll have to experiment with the exact proportions though.... Axehandle, if you can get this stuff, I think it would work admirably.... the m.p. of zircon is 2680 deg. C. !!!! You have access to a several ton press too, right? I was thinking about making zircon/kaolin tiles in a tile press (can rent one at the ceramics place for $4 an hour), I don't know how much it will help the strength though.

BromicAcid - 8-6-2005 at 10:23

IF... someone gets a good sulfur burner design that works. I found an interesting method to produce sulfuric acid that is simple and could easily be made continuous. The premise is to bubble SO2 and oxygen into a collum filled with water (in the experiments they used 100 ml) with a small precentage of manganese sulfate. The solutions can be made readily to concentrations of about 40% where the effectiveness of this procedure slacks off. Reading though the article it looks fairly promising (but I cannot upload it because it is >1 M).

Recovery of Sulfur Dioxide as Dilute Sulfuric Acid
Raymond L. Copson, John W. Payne;
Ind. Eng. Chem.; 1933; 25(8); 909-916.

axehandle - 8-6-2005 at 11:21

BromicAcid: Could you upload it to the FTP? It sounds very interesting.

BromicAcid - 8-6-2005 at 18:23

Not a problem, uploaded it to the FTP. Also uploaded it to my website for quick access for those who don't have FTP access.

SO2manganese.pdf

Pyridinium - 8-6-2005 at 19:37

Quote:

Originally posted by Jome
If a flow of SO2 is created somehow, why not bubble it into H2O2-solution to get H2SO4 instantly instead of using a catalyst to turn it into SO3 and then absorbing this into water

That very procedure appears in an old Chemcraft manual I used to have. I think it was from about 1953. Collect SO2 from burning sulfur, deliver it into a jar containing H2O2, then cork the jar and shake it up. Only problem was, you'd get maybe 3% sulfuric when you were done (grocery store peroxide).

It was still a good little experiment. I think that manual was from a set marked "ages 10 and up". The set had basic copper carbonate (malachite), sodium bisulfate, logwood (hematoxylin), cobalt chloride, etc... quite a variety. Now those were the days of good chemistry sets.

evilgecko - 8-6-2005 at 22:20

Very interesting experiment although curious to know how the manganese sulphate is removed after reaction. I might try this although need catalyst. Could I react managese (II) oxide with weak battery acid to produce manganese sulphate?
MnO + H2SO4 -> MnSO4 + H2O

BromicAcid - 9-6-2005 at 18:27

Many of the sulfates are for the most part insoluble in concentrated H2SO4 I was recently reading a paper on the recovery of sulfuric acid from waste waters that contained ferrous sulfate and when the solution was heated and concentrated to ~75% the ferrous sulfate precipiated out. So it may prove that during the concentration process the manganese salt would precipitate out.

Jome - 1-10-2005 at 14:25

MnO2+4HCl--->MnCl2+Cl2+2H2O. Then MnCl2 soln is filtered and the salt dried.
Now to the question: would addition of zinc or aluminium precipate Mn-metal from MnCl2 soln?

If so, making MnSO4 should be easy, just addning the obtained metallic Mn to copper sulphate.