Sciencemadness Discussion Board - main chemicals for home lab setup

main chemicals for home lab setup

the mad chemist - 22-9-2015 at 02:29

hi everyone,
just wondering any possible way to have some main chemicals(specially house hold ones) that help me make a lot of other complex chemicals and if you have any experience with these things please share it here or send me link to it
wish the best
the mad chemist

woelen - 22-9-2015 at 02:53

Reading this page may be helpful if you are starting and want to set up a home lab:

http://woelen.homescience.net/science/chem/misc/homelab.html

j_sum1 - 22-9-2015 at 02:55

No time for a full reply right now.
Your answer: it depends on what you are wanting to do.
I suggest you search. This Q gets asked regularly. It won't take too long before you find a list or a link to a list.
My suggestion: build stock and equipment project by project.

(edit)
I was going to recommend woelen's link.

[Edited on 22-9-2015 by j_sum1]

the mad chemist - 22-9-2015 at 02:56

good website but i mean if any one know the main key chemicals for making a lot of other chemicals
cheers

the mad chemist - 22-9-2015 at 02:58

more interested in making chemical for low prices and extraction of organic and inorganic compounds

also wow i got replys fairly fast thanks

[Edited on 22-9-2015 by the mad chemist]

Basic supplies

100PercentChemistry - 22-9-2015 at 03:02

When is started off I just scavenged the food, drug, and hardware stores. You'll need baking soda, and vinegar for spills and reactions. You will also need lye(drain cleaner) and sulfuric acid (drain cleaner). These two may not be pure, but will still work ok. Please go to
https://en.m.wikipedia.org/wiki/List_of_commonly_available_c...

I started by picking an experiment, and then buying the chemicals at the store, or online. After awhile I had a large selection of them.

For supplies I started out with a funnel, a glass rod, filter paper, some flasks and beakers, a graduated cylinder, and an alcohol burner.

Finally, for saftey get some good goggles, a face shield, a respirator(hardware store, a fire extinguisher, some latex gloves, and some chemical resistant gloves. Search up glove compatability chart.
Most chemicals a hard to find at a store, so buy them from Amazon, eBay, home science tools etc.

https://m.youtube.com/watch?v=xjbwk9f9mcY
https://m.youtube.com/watch?v=0k7-drcTl4M
https://m.youtube.com/watch?v=zhDypc8SCoE

the mad chemist - 22-9-2015 at 03:11

thanks just needed that i wish i could have the setup easy
regards the mad chemist

ave369 - 22-9-2015 at 08:19

In case if sulfuric acid drain opener is not available where you live (in my country, conc. sulfuric is a FSKN List IV chemical, which makes it illegal as an OTC consumer product), you should learn to "Boil the Bat". That is, boil down battery acid to concentrate it. This is what will become your new Pater Noster.

Upsilon - 22-9-2015 at 13:48

FYI you don't need to buy straight-up lye (NaOH), you can make it out of regular table salt via electrolysis.

ave369 - 22-9-2015 at 16:05

Quote: Originally posted by Upsilon

FYI you don't need to buy straight-up lye (NaOH), you can make it out of regular table salt via electrolysis.

Even that is not required. Regular drain openers (as opposed to those with sulfuric acid) are usually NaOH based. Especially convenient are dry and granulated ones, in which NaOH is in granules and everything else is a fine powder. Any old kitchen sieve can be used to separate NaOH from everything else. Sometimes you can find "Pure Lye Bead" openers, with these you do not even need the sieve.

KOH on the other hand... This you have to either buy, electrolyze from potassium fertilizers or sodium-free salt, or leach from old alkaline cells and then concentrate by boiling down.

[Edited on 23-9-2015 by ave369]

woelen - 22-9-2015 at 22:31

Quote: Originally posted by Upsilon

FYI you don't need to buy straight-up lye (NaOH), you can make it out of regular table salt via electrolysis.

Please, try it and report back on your results!

if you do some practical chemistry then you soon will discover that making (and isolating!!) basic chemicals can be very hard.

Upsilon - 23-9-2015 at 10:39

Quote: Originally posted by woelen

Quote: Originally posted by Upsilon

FYI you don't need to buy straight-up lye (NaOH), you can make it out of regular table salt via electrolysis.

Please, try it and report back on your results!

if you do some practical chemistry then you soon will discover that making (and isolating!!) basic chemicals can be very hard.

If you separate the setup into half cells connected by a salt bridge then it's really not that bad. As long as you can run the cathode cell to completion, there shouldn't be too much NaCl contamination left over. And there are ways to deal with any NaCl contamination if you need even higher purity.

macckone - 23-9-2015 at 12:40

Electrolysis for even a lab scale quantity is not easy.
Various forms of salt bridge are possible but you get contamination.
From my experience you can get a couple of percent out of an agar
bridge. And you have some agar in your solution as well as salt.

Membranes make it easy but they are very expensive. They give
a really high purity product. The cost of up to US$300 per sq ft
is a major drawback. You can purify a lot of drain cleaner for that price.

A mercury cell is not that easy either as the mercury amalgam will
solidify if it gets too high in sodium. And mercury is toxic.

A diaphram cell is much easier than the others and purifying your
sodium hydroxide then becomes the problem.

Having said all of that, purifying drain cleaner is not the worst way
to go if you have more time than money.

The other big chemical is sulfuric acid. If you master electrolysis,
then epsom salt is your friend. A diaphram cell or membrane cell
is necessary here. Epsom salt can also be decomposed to sulfur
trioxide and dioxide gas at extreme temperature (1100+C).

woelen - 23-9-2015 at 13:09

Quote: Originally posted by Upsilon

Quote: Originally posted by woelen

Quote: Originally posted by Upsilon

FYI you don't need to buy straight-up lye (NaOH), you can make it out of regular table salt via electrolysis.

Please, try it and report back on your results!

if you do some practical chemistry then you soon will discover that making (and isolating!!) basic chemicals can be very hard.

On paper many syntheses look simple and of course, there always are ways to purify things. But in practice this is HARD, very HARD! Try it, then you will see yourself. You can buy pure (99% NaOH) for a few euros (or dollars) per pound, and there is no substitute for that. I am doing home chemistry for 20 years or so by now and from experience I know that making, isolating and purifying new chemicals in many cases is very hard and requires a lot of work, decent equipment and a lot of patience. Many chemicals which are made from naturally occuring simple stuff like NaCl, CaCO3, N2 from air, water, etc. by the multitonne on an industrial scale are amazingly hard to make at home (e.g. NaOH, H2SO4, conc. HCl, HNO3). The basic reactions are very simple, but from an engineering perspective it is extemely hard.

NaOH and H2SO4 really are basic chemicals you need to buy. With these as starting point, you can make many other interesting chemicals relatively easily, using easy to obtain chemicals (e.g. HCl from NaCl, NH3 from NH4Cl or (NH4)2SO4, HNO3 from KNO3 or NaNO3). Many of these chemicals, however, also can be purchased easily in many countries (HNO3 becomes harder to obtain nowadays due to anti-terrorism regulations).

Upsilon - 23-9-2015 at 16:37

I actually am in the middle of an NaCl electrolysis right now. It's taking an extremely long time (about 2L of highly concentrated NaCl solution, using a 24V 0.5A DC adapter). I've separated the half cells and connected them with a salt bridge, and I'm using graphite electrodes I extracted from regular pencils. It's going to take several days of collective runtime to go all the way, so it'll be a while before I can share any results.

HNO3 is easier to create than NaOH, though. If you're able to work with a slightly contaminated sample, you can react a solution of calcium nitrate with sulfuric acid (both pretty cheap). Then just filter the calcium sulfate precipitate. A small amount of it will dissolve and contaminate the HNO3 (it's not much, it will be about 2.4 grams of calcium sulfate contamination per liter of acid); to prevent this barium nitrate can be used in place of calcium nitrate. Barium nitrate is a little expensive, though.

EDIT: It might be possible to use oxalic acid (still cheap) instead of sulfuric acid, since calcium oxalate is much less soluble than calcium sulfate. I have suspicions though that nitric acid would attack the calcium oxalate. This would be something to experiment with.

[Edited on 24-9-2015 by Upsilon]

ave369 - 24-9-2015 at 00:54

Quote: Originally posted by Upsilon

HNO3 is easier to create than NaOH, though. If you're able to work with a slightly contaminated sample, you can react a solution of calcium nitrate with sulfuric acid (both pretty cheap). Then just filter the calcium sulfate precipitate. A small amount of it will dissolve and contaminate the HNO3 (it's not much, it will be about 2.4 grams of calcium sulfate contamination per liter of acid); to prevent this barium nitrate can be used in place of calcium nitrate. Barium nitrate is a little expensive, though.
[Edited on 24-9-2015 by Upsilon]

Do you have a Buchner set for that? The precipitate of CaSO4 is huge and messy, and it's a pain in the ass to filter it through paper.

Upsilon - 24-9-2015 at 09:00

Quote: Originally posted by ave369

Quote: Originally posted by Upsilon

Do you have a Buchner set for that? The precipitate of CaSO4 is huge and messy, and it's a pain in the ass to filter it through paper.

It's doable with just a Buchner funnel and some filter paper. You'll just need some object to squeeze the liquid from the calcium sulfate while it's in the funnel. Sure, you'll get more out of it with vacuum distillation, but it gets pretty expensive for a working setup.

gdflp - 24-9-2015 at 10:58

Quote: Originally posted by Upsilon

No it's not possible at all, have you ever actually tried that before? There's no way you'll be able to filter a mixture that acidic with filter paper, it will tear in under a second. You will need at the very minimum a glass frit with the correct pore size so as not to get clogged. And removing calcium sulfate from a frit will be a pain in the ass, not to mention that decently sized frits aren't cheap. There's a reason that distillation is the common way to go when making nitric acid, and a distillation setup is not that expensive. If you buy Chinese glass, you can typically get one for under $40, and it can be used for a lot more than preparing nitric acid.

ave369 - 24-9-2015 at 11:44

It's possible if the acid is dilute enough. Say, battery acid diluted with equal amount of water, with calcium nitrate in stoichiometric amount. Did this, didn't eat through any paper, but getting rid of calcium sulfate is hell. I'd better distill some nitric acid from sulfuric & saltpeter in a retort. Did this yesterday, prepared 90+% nitric acid.

gdflp - 24-9-2015 at 15:12

Quote: Originally posted by ave369

It's possible if the acid is dilute enough. Say, battery acid diluted with equal amount of water, with calcium nitrate in stoichiometric amount. Did this, didn't eat through any paper, but getting rid of calcium sulfate is hell. I'd better distill some nitric acid from sulfuric & saltpeter in a retort. Did this yesterday, prepared 90+% nitric acid.

I was talking about making acid of a reasonable concentration, but I could see it being possible to filter a dilute solution. But as you saw for yourself, distillation is the easier method, and the only method if you want acid of a decent conc. in a good yield.

Upsilon - 24-9-2015 at 15:36

I do have a rough distillation setup (it uses rubber stoppers instead of glass joints, but I have all of the glassware needed). In theory, I could make a 68% solution by adding correct amounts of sulfuric acid, calcium nitrate, and water, which would then boil at exactly 121C? Sounds fairly simple.

gdflp - 24-9-2015 at 16:16

Quote: Originally posted by Upsilon

I do have a rough distillation setup (it uses rubber stoppers instead of glass joints, but I have all of the glassware needed). In theory, I could make a 68% solution by adding correct amounts of sulfuric acid, calcium nitrate, and water, which would then boil at exactly 121C? Sounds fairly simple.

Yes, but you can't distill conc. nitric acid in an apparatus where the vapors will come into contact with rubber. The hot vapors will destroy rubber quite rapidly.

Upsilon - 24-9-2015 at 16:43

Quote: Originally posted by gdflp

Quote: Originally posted by Upsilon

Yes, but you can't distill conc. nitric acid in an apparatus where the vapors will come into contact with rubber. The hot vapors will destroy rubber quite rapidly.

Would it be feasible, then, to wrap the rubber stoppers in Teflon tape? The vapors are traveling through glass tubes, so I would only need to worry about covering the exposed surfaces of the rubber. It'll make the stoppers slippery as hell in the flask opening, but it'll save me from buying extra glassware.

gdflp - 24-9-2015 at 18:49

I doubt that would work. In my experience, the nitric vapors have gotten through a ground glass joint greased with conc. sulfuric acid and destroyed my Keck clips every time. Attempting this with rubber fittings, even coated in Teflon tape, sounds like a disaster waiting to happen.

macckone - 24-9-2015 at 19:02

It is possible with the rubber stoppers wrapped in teflon tape.
But you need a special heat gun with an inert gas supply (plastic welder)
to make the tape actually fuse to itself and the rubber stoppers.
But don't plan on using the rubber stoppers more than
a couple of times.

You can do this in a crude manner with a hair dryer in an
aquarium filled with carbon dioxide.
You might be able to achieve the same thing in a toaster oven
with baking soda which would act as a carbon dioxide source.
I haven't tried either of these methods. A plastic welder
with inert gas isn't cheap though.

It is really easier to buy a glass vacuum
distillation set and a water aspirator vacuum pump.
You can get one of these for under $200, which isn't
cheap but is a lot better than breathing nitric.

Corrosive Joeseph - 24-9-2015 at 19:13

This page is a personal favorite of mine regarding general chemical aquisition............

http://makezine.com/setting-up-a-home-science-lab3/

macckone - 24-9-2015 at 19:18

+1 to gdflp, filtering gypsum with concentrated nitric acid is just not safe or even
doable. The only way this works is to let the gypsum settle (days or weeks) and
then decant off the nitric acid that isn't bound in the gypsum.

Also upsilon's attempt to make sodium hydroxide in a salt bridge cell
with 2L of salt solution and a .5 A supply is not really going to work well.
There is probably about 600g or so of salt. To reach 2% which is really
about the maximum for a salt bridge cell would mean making 40g or so
of sodium hydroxide. That is around 1 moles. At 26 amp-hours per mole,
that is going to be about 22 days at 10% efficiency and .5 amps. You can't
run to completion or get high efficiency with a salt bridge.

You can use a diaphram cell and get 10% or so solution but the efficiency is still
pretty low. Electrical efficiency of a homemade diaphram cell is likely to be
around 20% maximum. But you can get higher efficiency and solution concentration.
The key with a diaphram cell is ensuring there is no sodium hydroxide flow to
the chlorine side of the cell. This requires keeping the solution on the chlorine
side above the level of the sodium hydroxide side. In a long running cell
this requires constantly draining and replacing the solution.

In either case you have to purify the sodium hydroxide solution
and then dry it. Drying sodium hydroxide is not easy.

[Edited on 25-9-2015 by macckone]

Upsilon - 24-9-2015 at 19:37

Isn't most NaOH produced industrially via electrolysis though? What do they do that lets them run it to completion? Or do they not and have a method for removing the NaCl contaminant?

woelen - 24-9-2015 at 22:37

In the industrial processes, the electrolysis does not run to completion. The dissolved NaOH/NaCl mix (so called caustic brine) is evaporated in multiple stages, causing NaCl (and also some NaOH) to crystallize. The remaining caustic brine contains less NaCl and after several stages of evaporation, NaOH-purity can be better than 99%. At this stage, however, probably 90% of all produced NaOH is "waste", contaminated with a lot of NaCl. The "waste" product of the evaporation (NaCl/NaOH-mix) is fed back into the electrolysis cell so that the NaOH is not lost (subsequent electrolyses start off with some NaOH in it already).

In reality, this is not a discrete process as sketched above, but a continuous process of electrolysis, taking away caustic brine, evaporation and partial feedback of caustic brine to the cathode electrolyte cells, together with addition of fresh brine to the anode electrolyte cells. The energy needed for all these feedbacks mostly comes from the waste-heat of the electrolysis process itself. These feedbacks of "waste"-flows, "waste"-heat, and the staged evaporation of brine to get progressively more pure NaOH are marvels of engineering ingeniousity and certainly are not easily built at home. This is exactly why these industrial processes for making basic chemicals like NaOH are so hard to duplicate in the lab. Many of these processes only work on an industrial scale. The ingenious engineering makes these processes highly efficient, in terms of used energy and in terms of net yield (ratio of useful products to waste which must be dumped).

annaandherdad - 25-9-2015 at 06:34

Thanks for that explanation, woelen. I had always wondered about this myself (how they purify the NaOH). I suppose if you want really pure NaOH electrolysis is not a good method of production?

macckone - 25-9-2015 at 08:27

The three industrial methods are: mercury cell (being phased out), diaphram (requires purification), and membrane (most commercial operations use this).

The mercury cell and membrane can produce very pure sodium hydroxide.
Neither method actually runs to completion but the sodium chloride is completely
isolated from the sodium hydroxide. Membrane can only produce around 10%
solution but it is very pure. The mercury cell method can go to 50% but
it is being phased out due to the toxic waste it produces. The main drawback
for the home chemist is a membrane cost $300/sq ft. At $100-$200 per pound
for mercury the mercury cell is also quite expensive for the home chemist.

The diaphram method with a good diaphram is much less efficient and is
used in a few places for food grade sodium hydroxide (used in making pretzels).
But the sodium hydroxide contains substantial salt and requires extensive
purification. This is the method that is most useful for a home chemist
but you can't use the product without purification and it is not easy to
purify.

Purifying sodium hydroxide from a diaphram cell is not easy.
Woelen went into the difficulty. Industrially they rewash the salt
to dissolve the sodium hydroxide preferentially. And unlike a home
cell they can get 10% sodium hydroxide solution with high concentration
of salt. While a home cell is likely to only get up to 2% unless you
spend a lot of time on engineering. Plus you have to come up with a
way to constantly remove the mix while adding pure salt.

With any of these methods you need to purify the salt before you
use it for electrolysis if you want a pure product. As table salt is
often a mixture with silicates and other things that are safe to consume
but will contaminate your end product.

Another note, getting anhydrous sodium hydroxide adds another
level of complexity as you need to heat the sodium hydroxide well
above melting with a constant stream of absolutely dry carbon dioxide
free gas. Industrially this is air that has the carbon dioxide removed
with the conveniently available lye solution and then dried using a variety
of methods including condensing units and beds of drying agents.
The air is recylced as are the drying agents, the water from the
condensing units is very high purity and is fed back into the
various cells.

Quite frankly doing all of this is difficult in a home environment.
Although if you are doing it for the learning experience it can be
quite challenging and even fun.
It is easier to purify drain cleaner or just buy a lye based one.
In fact you might want to try purifying a drain cleaner first
as the process is a challenge and will prepare you for
cleaning up the crude lye from electrolysis.

Upsilon - 25-9-2015 at 08:28

Yeah, thanks for the info. It seems like large-scale industry always has the upper hand over the lab in terms of flexibility. I suppose that's to be expected though since they have profits at stake. So I guess household electrolysis is only useful for producing gases?

macckone - 25-9-2015 at 11:05

I would say household electrolysis can be useful.
But you need to know the limitations.
I think it is more for fun and technical ability than
generating a useful product.
But that is mostly why a lot of us do chemistry.

woelen - 25-9-2015 at 11:21

For some chemicals, household electrolysis can be useful. I myself made KClO3, KBrO3, Br2, and KIO3 in this way. I wrote webpages about these processes:

http://woelen.homescience.net/science/chem/exps/miniature_ch...
http://woelen.homescience.net/science/chem/exps/KBrO3_synth/...
http://woelen.homescience.net/science/chem/exps/OTC_bromine/...

For all experiments you need some chromate or dichromate as well. For this, in the meantime I also found a very easy way to make it, no need to isolate.

Use potassium chrome alum, or chromium sulfate and dissolve in as little as possible amount of water (e.g. 5 ml).
Add bleach (5% household) while gently heating and stirring without perfumes and detergents until you get a clear yellow solution (first the solution is turbid and then the precipitate redissolves again and the liquid becomes yellow).
The liquid, thus obtained, can be used in all electrolysis processes, described in the links, given above. For each 100 ml of liquid, add 2 ml or so of the yellow solution.

Chrome alum or chromium sulfate is easy to obtain, e.g. on eBay and it is non-toxic:
http://www.ebay.nl/itm/500g-Chromium-Potassium-Sulphate-high...

You can also buy potassium dichromate or sodium dichromate, ready for use. They are sold by many sellers on eBay (even more so than for chromium(III) salts), but they are toxic and inhalation of dust must be avoided at any cost.

ave369 - 25-9-2015 at 13:20

Quote: Originally posted by Upsilon

Would it be feasible, then, to wrap the rubber stoppers in Teflon tape?

Quote: Originally posted by macckone

buy a glass vacuum
distillation set and a water aspirator vacuum pump.
You can get one of these for under $200

Buy yourself a retort, man. Mine costed me about $5. It's a veritable nitric acid factory. And also useful for other things.

Upsilon - 25-9-2015 at 13:22

I just tried my own version of PTFE-coating a rubber stopper. I used Teflon tape and superglue with a #2 stopper. I started with 4 vertical wrappings to completely cover the bottom of the stopper. I then wound it horizontally around the sides of the stopper. All while applying superglue to the stopper to hold it down. I think it turned out pretty good, you can't see any exposed rubber or even any seams unless you look really closely.

It was tedious as hell and I managed to trash my fingers with superglue. There's also some residual superglue on the outside of the Teflon tape so I'll need to wash it with acid before using it. I'm not using this for distillation or anything; a stopper with a hole in it would make covering it with Teflon infinitely more complicated. This was mostly just for being able to store acids that attack rubber (like conc. sulfuric) in regular beer bottles.