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Tdep
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[*] posted on 13-11-2015 at 08:22


Quote: Originally posted by ave369  


Why not try a simple test? There is a ton of reagents that allow to detect trivalent iron. Rhodanide, cyanoferrate, tannic acid all give strong, easily detectable colors. Just remember to neutralize the acid beforehand if you use cyanoferrate.

[Edited on 13-11-2015 by ave369]


I have never tested because its never really mattered, I dont think ive ever had to do areaction that would be affected by a small amount of iron. I hardly do analytical chemistry, in fact the only time I ever use demineralised water is working with silver. Bit of metal contamination here and there doesnt worry me (except mercury in fish, I do worry about that given how much sushi I cant help but consume).
Are there other testing reagents? Oh wait, cyanoferrates are the things that give prussian blue as a positive yeah? Think I have some of that lying around from an old chemistry kit I gog when I was about 13...
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The Volatile Chemist
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[*] posted on 15-11-2015 at 14:02


Yeah, Ferrocyanide won't precipitate trivalent cations, I'm fairly certain (minus Fe3+).



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[*] posted on 16-11-2015 at 01:47


Quote: Originally posted by Upsilon  
Quote: Originally posted by ahill  

Chinese (ebay/aliexpress) glassware / distillation sets are fantastic value for money - the police _will_ (eventually) visit you if you order them. Unsettling, but not necessarily especially unpleasent.


Wait, what? Where do you live that they would actually do that? I ordered a distillation setup over a month ago, on eBay, from China, and I haven't heard squat about it.

same thing happened to me man, i admit i did go over board with an order from china. but about 2 months later the drug squad rocked up hoping to find a meth lab and after explaining were pretty cool with it all. the just took my larger flasks and all my condensers. qld too.
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[*] posted on 16-11-2015 at 02:52


Quote: Originally posted by tekkado  
Quote: Originally posted by Upsilon  
Quote: Originally posted by ahill  

Chinese (ebay/aliexpress) glassware / distillation sets are fantastic value for money - the police _will_ (eventually) visit you if you order them. Unsettling, but not necessarily especially unpleasent.


Wait, what? Where do you live that they would actually do that? I ordered a distillation setup over a month ago, on eBay, from China, and I haven't heard squat about it.

same thing happened to me man, i admit i did go over board with an order from china. but about 2 months later the drug squad rocked up hoping to find a meth lab and after explaining were pretty cool with it all. the just took my larger flasks and all my condensers. qld too.


What was the consequences if you didn't give them your flasks and condensers?
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[*] posted on 16-11-2015 at 03:28


Quote: Originally posted by The Volatile Chemist  
Yeah, Ferrocyanide won't precipitate trivalent cations, I'm fairly certain (minus Fe3+).


There are two kinds of cyanoferrate: ferrocyanide and ferricyanide. One results in Prussian blue with divalent iron, the other with trivalent.

[Edited on 16-11-2015 by ave369]




Smells like ammonia....
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[*] posted on 16-11-2015 at 04:41


Quote: Originally posted by HeYBrO  
Quote: Originally posted by tekkado  
Quote: Originally posted by Upsilon  
Quote: Originally posted by ahill  

Chinese (ebay/aliexpress) glassware / distillation sets are fantastic value for money - the police _will_ (eventually) visit you if you order them. Unsettling, but not necessarily especially unpleasent.


Wait, what? Where do you live that they would actually do that? I ordered a distillation setup over a month ago, on eBay, from China, and I haven't heard squat about it.

same thing happened to me man, i admit i did go over board with an order from china. but about 2 months later the drug squad rocked up hoping to find a meth lab and after explaining were pretty cool with it all. the just took my larger flasks and all my condensers. qld too.


What was the consequences if you didn't give them your flasks and condensers?

They were gonna take it regardless unless i got an eud. Theyre just concerned with diversion and your intentions.
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[*] posted on 16-11-2015 at 14:40


Quote: Originally posted by tekkado  
Quote: Originally posted by HeYBrO  
Quote: Originally posted by tekkado  
Quote: Originally posted by Upsilon  
Quote: Originally posted by ahill  

Chinese (ebay/aliexpress) glassware / distillation sets are fantastic value for money - the police _will_ (eventually) visit you if you order them. Unsettling, but not necessarily especially unpleasent.


Wait, what? Where do you live that they would actually do that? I ordered a distillation setup over a month ago, on eBay, from China, and I haven't heard squat about it.

same thing happened to me man, i admit i did go over board with an order from china. but about 2 months later the drug squad rocked up hoping to find a meth lab and after explaining were pretty cool with it all. the just took my larger flasks and all my condensers. qld too.


What was the consequences if you didn't give them your flasks and condensers?

They were gonna take it regardless unless i got an eud. Theyre just concerned with diversion and your intentions.


Makes no sense since its not illegal, but i respect your choice not to get into strife with the austhorites. EUDs are a bit of a token effort to stop illegal use of glassware, I mean how is a piece of paper protecting anyone? People can just buy it online anyway. Did you just buy more condensers from a local supplier with an EUD then?
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[*] posted on 16-11-2015 at 15:54


^sadly no. Between study and work i havent had the time for experimenting or anything.
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The Volatile Chemist
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[*] posted on 19-11-2015 at 10:14


Quote: Originally posted by ave369  
Quote: Originally posted by The Volatile Chemist  
Yeah, Ferrocyanide won't precipitate trivalent cations, I'm fairly certain (minus Fe3+).


There are two kinds of cyanoferrate: ferrocyanide and ferricyanide. One results in Prussian blue with divalent iron, the other with trivalent.

[Edited on 16-11-2015 by ave369]

Yes, I know. But I was talking about the lack of +3 cation precipitates for the latter, so I brought it up. I'm not certain if the former precipitates any trivalent cations.




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[*] posted on 25-11-2015 at 02:06


Hello, sorry for the wait.
I have found an alternative for methanol (available but only in huge quantities) in the flame colouring experiment - hand sanitizer (normal ethanol burns yellow). Also, about HCl, what how would you handle 32% (it would fume a lot)? And would it be safe to heat up around 3 molar hcl in the borax + hcl -> boric acid +nacl experiment for green flame? CuSO4 is easier to obtain as animal supplement, but H2O2 35% is only available in food grade. Auschem is a good site however it only has mostly solid chemicals.

Also a question on titration - would it be ok to substitute measuring cylinder for burette if accuracy is not that important (+-0.5M or so)? Also if accuracy is not important (+- 1M) would substituting own dissolved NaOH (standard volumetric flask procedure is used but NaOH absorbs water, NaOH from unopened container) still skew the titration results a lot? It's very hard to find standardised solutions here.

Thanks for all the responses.
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[*] posted on 25-11-2015 at 02:59


for methanol try a performance automotive shop, that’s where I found mine
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[*] posted on 28-11-2015 at 09:16


Quote: Originally posted by Copper  
Hello, sorry for the wait.
I have found an alternative for methanol (available but only in huge quantities) in the flame colouring experiment - hand sanitizer (normal ethanol burns yellow). Also, about HCl, what how would you handle 32% (it would fume a lot)? And would it be safe to heat up around 3 molar hcl in the borax + hcl -> boric acid +nacl experiment for green flame? CuSO4 is easier to obtain as animal supplement, but H2O2 35% is only available in food grade. Auschem is a good site however it only has mostly solid chemicals.

Also a question on titration - would it be ok to substitute measuring cylinder for burette if accuracy is not that important (+-0.5M or so)? Also if accuracy is not important (+- 1M) would substituting own dissolved NaOH (standard volumetric flask procedure is used but NaOH absorbs water, NaOH from unopened container) still skew the titration results a lot? It's very hard to find standardised solutions here.

Thanks for all the responses.

HCl sort-of fumes, but small quantities are fine to use in a ventilated area. Just protect your eyes and don't breath in the fumes.
+/- 1M should be achieved with NaOH from a container. You might heat it up a bit first, though. A Graduated cylinder should be fine for +/- 0.5M, though I wouldn't trust it past that. Be sure to use a good indicator, too. pH strips may not cut it, as you'll have to use a lot of them in a single titration. Phenolphthalein is the best. Also, a stir-plate is very helpful.




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[*] posted on 28-11-2015 at 16:25


Ok thanks, do you think attempting to standardised Na2CO3 might work better than NaOH? (Na2CO3 in anhydrous form is used)? Sodium carbonate solution made in 500mL volumetric flask, digital scale to 2dp. Then maybe standardising HCl to that and the NaOH to the HCl? Would that be able to determine the concentration more accurately?

About the indicator, I have powder phenolphthalein, but I don't know what to store solution in if I make it (say I make 200mL of 1% at a time, then I put 30mL in a dropper, but other 170mL). Apparently phenolphthalein decomposes upon light so I can't use me semi-clear HDPE container to store them in. Large amber bottles are kind of hard to find.

Thanks
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[*] posted on 29-11-2015 at 03:15


Beer bottle and some parafilm works for short-mid term storage of light sensitive's. You can get uncrimped bottle caps from homebrew stores/woolworths.

For small amounts, pharmacies will sell empty amberglass bottles, or else some kind of <$5 product which comes in said bottles.

Although as an addendum, phenolpthalein indicator solution has always been stored/used in clear glass bottles at my tafe lab.

Na2CO3 doesn't need to be standardized. It's a primary standard. Simply weigh and dissolve in deionized water in a volumetric flask.

We use potassium hydrogen pthalate for titrating bases in the lab, it also being a primary standard. I tried to buy KHP from Australian scientific at the storefront(I live nearby) but was told I needed an EUD. I don't have a problem signing EUD's and have done so for previous purchases, but I got a bit annoyed as I am pretty sure it's not normally an EUD requiring product. Especially given it's usability is limited specifically to things no kewl/cook would have the slightest interest in.

[Edited on 29-11-2015 by Mesa]
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[*] posted on 29-11-2015 at 04:39


Copper, if you buy peroxide from a pharmacy and use it (easy to do) then you have some perfectly good amber bottles with nice teflon caps.



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[*] posted on 29-11-2015 at 12:46


Forgot to mention, Melbourne food depot is a decent source for a surprising array of chemicals otherwise uncommon/unavailable OTC.

propionate salts, nitrite salts, etc. to name a few.
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[*] posted on 2-12-2015 at 12:20


Interesting. I'm surprised, I've now just said to myself "wish I lived in Aussie"...



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[*] posted on 16-1-2016 at 23:00


Quote: Originally posted by ahill  

I dont know _what_ the impurity in their HCl is - iron sounds plausable. The MDS doesnt mention anything. I had some from years ago, and recently bought a different branded one from them - but it seems to have the same issues - leaves a greyish crystalline residue when evaporated to dryness. Addition of H2O2 causes an instant reddish brown discolouration. Some reactions I've done with it that I would expected to have been colourless were more like mango puree !


I bought two gallons of dirt cheap 29% HCl from Home Depot a couple years back. They sell it for swimming pools and it has a yellow impurity that we figured must be an iron compound. Simple distillation will bring over just the clear HCl and leave the yellow impurity in the boiling flask. It's time consuming, but makes for a cheap OTC source of HCl.
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The Volatile Chemist
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[*] posted on 20-1-2016 at 17:45


Quote: Originally posted by kt5000  
Quote: Originally posted by ahill  

I dont know _what_ the impurity in their HCl is - iron sounds plausable. The MDS doesnt mention anything. I had some from years ago, and recently bought a different branded one from them - but it seems to have the same issues - leaves a greyish crystalline residue when evaporated to dryness. Addition of H2O2 causes an instant reddish brown discolouration. Some reactions I've done with it that I would expected to have been colourless were more like mango puree !


I bought two gallons of dirt cheap 29% HCl from Home Depot a couple years back. They sell it for swimming pools and it has a yellow impurity that we figured must be an iron compound. Simple distillation will bring over just the clear HCl and leave the yellow impurity in the boiling flask. It's time consuming, but makes for a cheap OTC source of HCl.

Really, simple distillation? I don't say this sardonically, I just mean that I would assume one needs a vacuum set-up with ground glass, not because it's hard to get to 'come over' but because of the fumes. Can one really do it with a distillation flask, receiving flask, condenser, and rubber stoppers?




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[*] posted on 20-1-2016 at 18:46


Quote: Originally posted by The Volatile Chemist  
Quote: Originally posted by kt5000  
Quote: Originally posted by ahill  

I dont know _what_ the impurity in their HCl is - iron sounds plausable. The MDS doesnt mention anything. I had some from years ago, and recently bought a different branded one from them - but it seems to have the same issues - leaves a greyish crystalline residue when evaporated to dryness. Addition of H2O2 causes an instant reddish brown discolouration. Some reactions I've done with it that I would expected to have been colourless were more like mango puree !


I bought two gallons of dirt cheap 29% HCl from Home Depot a couple years back. They sell it for swimming pools and it has a yellow impurity that we figured must be an iron compound. Simple distillation will bring over just the clear HCl and leave the yellow impurity in the boiling flask. It's time consuming, but makes for a cheap OTC source of HCl.

Really, simple distillation? I don't say this sardonically, I just mean that I would assume one needs a vacuum set-up with ground glass, not because it's hard to get to 'come over' but because of the fumes. Can one really do it with a distillation flask, receiving flask, condenser, and rubber stoppers?

Sure. Just do it outside or somewhere else with ventilation where there's nothing around to rust. And, since HCl forms a 20% azeotrope with water, distilling 29% will lose you about a third of your HCl as gas. Dilute first.
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[*] posted on 20-1-2016 at 18:57


Quote: Originally posted by Etaoin Shrdlu  
Quote: Originally posted by The Volatile Chemist  
Quote: Originally posted by kt5000  
Quote: Originally posted by ahill  

I dont know _what_ the impurity in their HCl is - iron sounds plausable. The MDS doesnt mention anything. I had some from years ago, and recently bought a different branded one from them - but it seems to have the same issues - leaves a greyish crystalline residue when evaporated to dryness. Addition of H2O2 causes an instant reddish brown discolouration. Some reactions I've done with it that I would expected to have been colourless were more like mango puree !


I bought two gallons of dirt cheap 29% HCl from Home Depot a couple years back. They sell it for swimming pools and it has a yellow impurity that we figured must be an iron compound. Simple distillation will bring over just the clear HCl and leave the yellow impurity in the boiling flask. It's time consuming, but makes for a cheap OTC source of HCl.

Really, simple distillation? I don't say this sardonically, I just mean that I would assume one needs a vacuum set-up with ground glass, not because it's hard to get to 'come over' but because of the fumes. Can one really do it with a distillation flask, receiving flask, condenser, and rubber stoppers?

Sure. Just do it outside or somewhere else with ventilation where there's nothing around to rust. And, since HCl forms a 20% azeotrope with water, distilling 29% will lose you about a third of your HCl as gas. Dilute first.

(Sorry about the giant chunk of text)
Wow, that's great. I didn't know that at all, thanks. I'll have to try that this summer. Sounds like fun.




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