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OneEyedPyro
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[*] posted on 16-4-2016 at 01:03
Labware and chemical recommendations


After a couple years of using what little equipment I could improvise and chemicals sourced from hardware stores I've decided that it's about time to drop the cash on some real labware as well as some less easily sourced chemicals.

Any ideas for chemicals/labware that will allow for a wide range of synthesis/experiments and more importantly some of the basic items that I may be overlooking?

I already have or plan to get the major acids, bases and solvents (eg HCl, HNO₃, H₂SO₄, NaOH, alcohols, acetone), I also plan on getting a distillation setup, various flasks and beakers, a sep funnel, stir/hot plate, thermometers, filtering flask/buchner among other things.

Any suggestions are welcome.
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[*] posted on 16-4-2016 at 01:05


Ebay !



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JJay
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[*] posted on 16-4-2016 at 04:39


Sodium bromide, potassium iodide, potassium ferrocyanide, copper sulphate, potassium dichromate, diethyl ether, chloroform, DCM, sodium carbonate, cetyl alcohol, sodium bisulphate, sulfamic acid, aluminum powder, mercury (careful!)), tartaric acids , urea, TCCA, iron oxides, iron filings, copper, nickel, sodium silicate, activated carbon, diatomaceous earth, barium chloride, potassium iodate, phosphorus oxychloride, sodium borohydride, toluene, sodium benzoate, pH paper, sodium, ammonium nitrate, calcium chloride, silver nitrate, sodium chloride, potassium nitrate, magnesium sulfate, hydrogen peroxide ....

One thing I have wanted lately is a source of cobalt.
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MrMario
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[*] posted on 16-4-2016 at 06:51


Deschem is a very good ebay glassware seller. I ordered several times now and if something was not right he fixed it by resending or refunding the item.
Some very handful items; 500ml/250ml/50ml Beakers (Good for crystallizations/evaportation and reactions), (500ml/250ml) Three-necked roundbottom flask that can attach multiple items to it (Gas generator/Thermometer/(Reflux)condensor/Stoppers), Receiving Rb. flasks 250ml/100ml/50ml, Liebig condensor (prefered), Three-neck adapter/Vacuum adapter/Thermometer adapter) and a lot of stoppers and clamps :)

For chemicals the most common ones are a good basis:
Acids: HCl, H2SO4, Acetic Acid
Bases: NaOH/KOH, NH4
Solvents: Ethanol, Methanol, DiChloroMethane, Chloroform, Diethyl Ether, Acetone, Hexane/Heptane, Petroleum Ether (Cheap solvent/easy evaporation)
Salts: NaCl, Na2CO3, K2CO3 (good drying agent and neutralisation), MgSO4, CaCl2, CuSO4, NH4Cl, NaNO2 (useful for Diazonium salts), Urea, NaBr
Metals: Al, Mg (turnings for grignards), Sn, Fe, Na/K (drying and reagent)
Misc: Ca(ClO)2 for chlorine generator

And very important; get a good hotplate stirrer, a good one will last very long and you use it often to heat/mix so it is wel invested.

Many things can be made from this list that can be used in futher synthesis. I think this is a pretty good starting list and you can always expand on this with more complex and harder materials. (You can buy Na/K from ebay, otherwise it is hard to get)


[Edited on 16-4-2016 by MrMario]
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MrMario
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[*] posted on 16-4-2016 at 06:59


Quote: Originally posted by JJay  


One thing I have wanted lately is a source of cobalt.


Buy some Cobalt Carbonate from a pottery store and you can make many salts from it. Or use electrolysis to make Co metal :)
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ave369
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[*] posted on 16-4-2016 at 08:22


You don't have to buy major acids. They can be whipped up from nothing if you have the glassware.

You buy sulfuric acid as battery acid, then boil it to concentrate. This you use to distill nitric acid from saltpeter. Hydrochloric acid can be made even from non-boiled Bat, mix it with table salt and distill.




Smells like ammonia....
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OneEyedPyro
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[*] posted on 16-4-2016 at 10:46


Many great suggestions I had not thought of to add to my list JJay, thanks a lot!

MrMario, pet ether, acetic acid and sodium nitrite were some reagents I had completely forgot, thanks buddy :D

ave369, I have pretty much all the major acids sourced from hardware stores and such with the exception being HNO₃ (which I'm quite excited to make once I get my distillation setup).

So far I'm only up to around $650, my budget is $1000. Keep the ideas coming :D


[Edited on 16-4-2016 by OneEyedPyro]
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JJay
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[*] posted on 17-4-2016 at 09:55


Elemental sulfur is popular. Potassium permanganate is a must-have. Acetone is also a must-have.

I like to keep a half dozen 250 mL Erlenmeyer flasks sitting around, and I have an array of other sizes.

You'll want a bunch of jointware. You can get by with only one condenser, but you'll want more eventually.

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OneEyedPyro
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[*] posted on 18-4-2016 at 16:50


Elemental sulfur is something I've been meaning to get for my element collection, I was going to purify and recrystallize some with toluene from gardening sulfur.

I was wondering what the best type and size condenser is the best all around? The kit I'm buying comes with a small West style condenser but I was thinking about buying a 400mm liebig too.

Also, what benefit or drawback does a PTFE stopcock have over a plain glass one? They are the same price give or take a few dollars.


[Edited on 19-4-2016 by OneEyedPyro]
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[*] posted on 18-4-2016 at 17:45


Quote: Originally posted by OneEyedPyro  
Elemental sulfur is something I've been meaning to get for my element collection, I was going to purify and recrystallize some toluene from gardening sulfur.

I was wondering what the best type and size condenser is the best all around? The kit I'm buying comes with a small West style condenser but I was thinking about buying a 400mm liebig too.

Also, what benefit or drawback does a PTFE have over a plain glass one? The are the same price give or take a few dollars.


I prefer 300mm Liebig for almost all distillations. I have used it to distill things with boiling points ranging between 35˚C all the way up to some things that boil at 360˚C with no problem. But for super volatile materials like bromine I prefer a longer one, maybe a 400mm. (I have distilled bromine with my 300mm, but some fumes escaped the end.) PTFE is better than glass with no exceptions (99% of the time). Glass stopcocks can only be used with acidic media, bases will cause them to freeze and eventually leak. This is why glassware with glass stopcocks are sometimes marketed as "acidic media glassware".
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JJay
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[*] posted on 18-4-2016 at 22:14


I also have a 30mm Liebig that I use for almost all distillations, and it works well in most reflux reactions. I also have a 40mm Graham condenser for ether and bromine, and I'd probably get a 60mm reflux (Dimroth) condenser if I had the money. I'd also like an air condenser for distilling sulfuric acid and a Dewar condenser for dry ice. Most soxhlet sets come with a Allihn condenser. But really, a 30mm Liebig is completely sufficient in 90% of cases and workable, if not completely ideal, in 99%.

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Orenousername
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[*] posted on 18-4-2016 at 22:18


Quote: Originally posted by ave369  
Hydrochloric acid can be made even from non-boiled Bat, mix it with table salt and distill.


Distill hydrochloric acid? Are you sure? Am I missing something here?
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OneEyedPyro
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[*] posted on 19-4-2016 at 19:47


Another question, exactly how is a fractional distillation performed and what's the ideal condenser for the job?

I know the idea is to separate two compounds with similar volatility by having the less volatile liquid condense back into the flask being heated the while the less volatile one is allowed to escape past the first condenser and is collected.



[Edited on 20-4-2016 by OneEyedPyro]
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MrMario
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[*] posted on 19-4-2016 at 22:20


Same setup as simple distillation but with an additional fractionating column (vigreux or packed column).
Often you have to isolate it with some glasswool or aluminium to prevent heatloss.
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NitreRat
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[*] posted on 9-5-2016 at 14:51


Quote: Originally posted by MrMario  
Same setup as simple distillation but with an additional fractionating column (vigreux or packed column).
Often you have to isolate it with some glasswool or aluminium to prevent heatloss.


I understand why people insulate there mantles and hotplates but I often see people insulate their fractionating columns which seems a little counter-intuitive to me. Surely an insulated column is just as effective as a shorter column? Isn't the point of a condenser to loose heat, not trap it? But what do I know? Maybe it improves fractional separation or reduces climate change...
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[*] posted on 9-5-2016 at 15:02


Insulated column has a gentler thermal gradient over its length. That means that a 1°C temperature change occurs over a longer physical distance and therefore you get better separation of components with close boiling points.

Of course you then get the difficulty of accurately controlling the heat input. You want some refluxing in your vigreux. If all the gases go straight through then you don't get the separation you are after.




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[*] posted on 9-5-2016 at 17:05


Quote: Originally posted by j_sum1  
Insulated column has a gentler thermal gradient over its length. That means that a 1°C temperature change occurs over a longer physical distance and therefore you get better separation of components with close boiling points.

Of course you then get the difficulty of accurately controlling the heat input. You want some refluxing in your vigreux. If all the gases go straight through then you don't get the separation you are after.


Thanks for the nice explanation. I must have learned more chemistry from browsing this forum than I did in the three years I payed to learn it for my degree.
I don't think I'll ever truly get my head around vapor pressures. Azeotropes are like voodoo magic to me. How can steam boil compounds which normally boil at >300°C? Luckily there's wikipedia, so I don't need to understand. I just need to be able to read values off a table.
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Chem Rage
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[*] posted on 11-5-2016 at 01:55


Quote: Originally posted by Orenousername  
Quote: Originally posted by ave369  
Hydrochloric acid can be made even from non-boiled Bat, mix it with table salt and distill.


Distill hydrochloric acid? Are you sure? Am I missing something here?


To save your precious H2SO4, you can actually synthesise some volatile acids like HCl and acetic by distillation from a mixture of the corresponding chloride or acetate salt with sodium hydrogen sulphate (NaHSO4), which is cheaper and more readily available OTC than H2SO4.

Use the procedure demonstrated by Nerd Rage.
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[*] posted on 11-5-2016 at 02:29


Sodium acetate can be prepared from vinegar and NaHCO3, or so I think. Wouldn't it be easier to just brute-force distill vinegar with a Bunsen burner?
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Chem Rage
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[*] posted on 11-5-2016 at 03:04


Quote: Originally posted by Eosin Y  
Sodium acetate can be prepared from vinegar and NaHCO3, or so I think. Wouldn't it be easier to just brute-force distilled vinegar with a Bunsen burner?


Yes, sodium acetate could be prepared from vinegar and sodium bicarbonate, but quite pure sodium acetate is so cheaply and readily available that I personally would rather buy it. Unless, of course, you are interested in the chemistry involved and get a buzz out of making your reagents from scratch.

Not a good idea to attempt simple distillation of dilute acetic acid:
1. Acetic acid and water have similar boiling points and for this reason dilute acetic acid (in the form of culinary/household vinegar for example) is not easy to concentrate by conventional distillation. You could try azeotropic distillation if you have the glassware and chemicals; see here: http://www.google.com/patents/US5160412

2. Try to avoid using a bunsen burner in the lab when organics are involved. Aside from the obvious flammability issue, the heat is often too aggressive compared to that of a hot plate or heating mantle, and can thermally decompose some organics, although a direct flame as a heat source is necessary for some dry distillations. Acetic acid vapours are actually flammable, as is glacial acetic acid. At least for organic chemistry, the heat provided by hotplates and heating mantles is more than sufficient.

[Edited on 11-5-2016 by Chem Rage]

[Edited on 11-5-2016 by Chem Rage]

[Edited on 11-5-2016 by Chem Rage]

[Edited on 11-5-2016 by Chem Rage]
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[*] posted on 11-5-2016 at 03:32


Ah. Just out of interest, exactly how controllable are hotplates? Are they within 50 or 5 degrees of the heat displayed on an LCD display on a digital hotplate?
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[*] posted on 11-5-2016 at 05:21


Quote: Originally posted by Eosin Y  
Ah. Just out of interest, exactly how controllable are hotplates? Are they within 50 or 5 degrees of the heat displayed on an LCD display on a digital hotplate?


A modern, well-constructed lab hotplate has a very high degree of controllability and precision. There are so many different models to choose from that you are spoilt for choice. Go for the best model you can afford, and ensure that it has a mechanical stirrer built into it.
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[*] posted on 11-5-2016 at 05:23


I'm on a limited budget, and I'll do my best to find a good one.
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XeonTheMGPony
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[*] posted on 11-5-2016 at 07:01


Lab gear is like any tool, it all starts with what you want to do.

Once you know what you want to do you design a process to get the resualt.

In example, I need acids, and I need to do thing that needs to be refluxed.

So acids: Round bottom flasks, I like to do large batches, so I want large rbf's
Condenser longer one lets me push it fast, or for normal speed gives me larger yield, Now reducing pressure lets me use lower temps.

SO: 2L rbf, 300mm liebig condenser, Vacuum take off adapter, 1L rbf

Now, for refluxing, I want to select what stayes and what goes or nothing, I want to be able to reload material if required. So best fit for my goals?

Allihn wet jacketed condenser, RBF, 24/40 plug. This meets the goal criteria.

So for this it starts at the end and you work your way to the beginning, such as, what do you want to make, then how much and fast determines the size!

The rest of the tools that are not tied to the process its self in a sense, are lots of thermometers, stands and clamps, hot plates so forth.
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XeonTheMGPony
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[*] posted on 11-5-2016 at 07:08


Quote: Originally posted by Eosin Y  
Ah. Just out of interest, exactly how controllable are hotplates? Are they within 50 or 5 degrees of the heat displayed on an LCD display on a digital hotplate?


you never rely on one method of monitoring temp, allot of process work is about care full control of the variables such as temp, flow, pressure and such, for us temp is a very big one.

You need to be able to track temps well for that you want accurate thermometers with that any heat source is precise! I use a simple 2 burner hot plate from the thrift store! Plus a good set of thermometers! -50 - 50c / 0 - 50c / -10c - 110c

Tighter the scale range the higher the accuracy. Your first and most important tool IMO is a good thermometer set, and a good hydrometer set.

You can't work when blind!

Forgot a simple calibration test: Take distilled water and make a clean ice cube crush in a clean baggie and mix with more distilled water in a small beaker. Cover with cellophane and let sit wrapped in a towel for 2 to 3 minutes.

Place thermometer in this and let sit for 3 or more minutes. it should read pretty dead on 0C, 32F. Much off this your calibration is bad! Get refund. Calibration for boiling points is more complex as you must factor in sea level pressure differences accurately.

[Edited on 11-5-2016 by XeonTheMGPony]

[Edited on 11-5-2016 by XeonTheMGPony]
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