Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Starting a lab, striking the right balance (beginners please read).
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

thumbup.gif posted on 23-1-2013 at 12:05
Starting a lab, striking the right balance (beginners please read).


Oftentimes, when starting a laboratory, the newly initiated have a difficult time striking the balance between what to buy, and what to make. This was my case, when I began as well, so I feel it's necessary to resolve this issue clearly so as to avoid repeating mistakes.

For example, making sulfuric acid makes for a decent discussion, but it has been tried before, and many have found that it's too much work and not rewarding enough for the effort required. In few words, there are better things to do.

I took the time to write a list of essential chemicals from which almost any inorganic chemical can be made. I think this is a comprehensive list of chemicals for any home chemist.

Here were the criteria for the list:
The chemicals have to be,
-mostly unregulated
-cheap
-easy to obtain because of widespread use in industry/photography/food processing etc...

Attachment: List of Essential Materials.docx (99kB)
This file has been downloaded 625 times

Many of you might wonder why some things are not on the list, like bromine, phosphorus, Et2O, HNO3, sodium metal, oleum, hydrazine, iodine, and sodium cyanide. This is because in most cases these chemicals are easier to make than to buy.

Some reagents I marked with an asterisk. The reasons vary, in the case of lead, gallium, and mercury, they are not essential elements of a lab, but could come in handy in organic syntheses. The same goes for chromium trioxide.

As for ammonium nitrate, I wish things were different, but its use in fertilisers is declining because terrorists and morons think that making fertiliser bombs is cool, or should I say k3W1. I vaguely remember the days where one could walk into a store and ask for some ammonium nitrate fertilizer, no raised eyebrows, no questions asked. Those days are gone, and obtaining ammonium nitrate is not as easy, or safe, as it once was.

A regulated power supply comes in handy for electrochemistry; a tube furnace comes in very handy for those considering challenging organic and inorganic syntheses, but it is not necessary for starting out.

You might also notice that my list of organic chemicals is rather short. The primary reason is that in organic chemistry, there are relatively few organic chemicals that are useful for every synthesis. Solvents are the major exception, so I provided a list of common useful solvents.

I hope at least some of you will find this useful.




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
kavu
Hazard to Others
***




Posts: 207
Registered: 11-9-2011
Location: Scandinavia
Member Is Offline

Mood: To understand is to synthesize

[*] posted on 23-1-2013 at 12:15


I would tweak the list of solvents a bit. Most used solvents in (organic) chemistry lab are hexane, ethyl acetate and DCM. An important consideration in starting a home lab is the waste management. How and where to dispose halogenated solvent waste, heavy metal waste and so forth.
View user's profile View All Posts By User
Hexavalent
International Hazard
*****




Posts: 1564
Registered: 29-12-2011
Location: Wales, UK
Member Is Offline

Mood: Pericyclic

[*] posted on 23-1-2013 at 15:01


I would also add nitric acid to the list of mineral acids (for instance, I have a small bottle of lactic acid, and, with the exception of making lactate salts, I have never found a productive use for it - conversely, I feel that nitric acid is a versatile reagent for the amateur and has many uses.): it can often be purchased online, or can be made if necessary using relatively simple techniques.



"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 23-1-2013 at 19:54


@Hexavalent
I completely agree, nitric acid is a very versatile acid. I also have to say that it's sometimes more convenient to produce nitric acid in situ when performing a nitration as opposed to just adding the pure acid.
I did not include it because I felt that its synthesis was simple and reliable enough to carry out when a need for nitric acid arose.

I admit lactic acid may not be equally useful for everyone. I use it pretty often to make saline solutions and buffers, but that's just me.

@kavu
I included cyclohexane in the list, it's not that different (chemically) from straight chained or branched hexanes. The same goes for chloroform and DCM. Halogenated waste can be disposed of in several different ways. The best way I know is to oxidise chloroform with an excess of hypochlorite to form formate, which can be washed down the drain. Usually though, you try to recover as much of the chloroform/DCM by distillation before cleaning the glassware. Another option is to let the containers that contained halogenated alkanes dry outside to let the solvent evaporate off.




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
Xenon1898
Harmless
*




Posts: 49
Registered: 19-1-2013
Location: United States
Member Is Offline

Mood: Researching

[*] posted on 23-1-2013 at 22:05
List of Reactions?


Thanks for the topic, this is very useful.

Now that we have the essential starting materials.... what to do with them? Seriously, is there a downloadable list of chemical reactions somewhere that would reasonably match up with this kind of basic materials list that is reasonable to synthesize in a home lab? I suppose there are millions of things that could be made, and I find a few rxn databases on the Internet. But I feel like I am re-inventing the wheel by scrounging for data on each individual reaction to make my list of reactions tailored to a home chemist (the db's I've found require searching one element or compound at a time and return one reaction at a time).




“If we knew what it was we were doing, it would not be called research, would it?”

-Albert Einstein
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 24-1-2013 at 07:31


A list of reactions is something that many people have tried and failed with. This doesn't mean that there are no resources, it just depends on your level of understanding of chemistry. This forum alone has a large library on everything from industrial chemistry to home chemistry.

I understand why you think that a lot of chemistry at your point is like re-inventing the wheel. That's because inorganic reactions can be separated into three groups, metathesis, single replacement, and decomposition. Metathesis reaction are often the easiest, but also the most useless, decomposition reactions can be both. Decomposing sodium bicarbonate to sodium carbonate is easily done on a stove while the decomposition of calcium carbonate to calcium oxide requires very high temperatures and a significant level of skill.

Redox reactions are the most useful in inorganic chemistry (in my mind). This is where you react a reducing agent with an oxidising agent to give something completely new. Alluding to single replacement reactions, dropping a piece of zinc metal into a solution of copper sulfate is a classic redox reaction, the copper gets reduced and precipitates from solution while the zinc gets oxidized and goes into solution.

Still, single replacement reactions are not very useful, what you really want to look for, are complex redox reactions whereby anions are oxidised or reduced. For example, to produce elemental phosphorus, you need to reduce the most common form of phosphorus, phosphate (PO4-3). Here is the general reaction:

2 Ca3(PO4)2 + 6 SiO2 + 10 C → 6CaSiO3 + 10 CO + P4
Another example is the carbothermal reduction of calcium sulfate to calcium sulfide:
CaSO4 + 2 C → CaS + 2 CO2

These are difficult reactions to perform, requiring high temperatures, but some are a bit easier. The production of sodium cyanide from cyanate is heavily documented on this forum. The reduction proceeds with powdered carbon as a reducing agent (surprise!) and the synthesis only requires moderate heat, about 400-500C last time I checked. Sodium cyanate can be made by heating urea with sodium carbonate.

I suggest trying one reaction that hasn't been documented yet on this site, making sodium dithionite from sodium bisulfite and zinc metal. There are numerous reports on the use of sodium dithionite as a reducing agent in organic chemistry where agents like sodium borohydride or lithium aluminium hydride would have had similar effectiveness. The difference is that one is easier to obtain, and cheaper than the other.




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
Xenon1898
Harmless
*




Posts: 49
Registered: 19-1-2013
Location: United States
Member Is Offline

Mood: Researching

[*] posted on 24-1-2013 at 17:41


Ah thank you, I appreciate the response. My question of a list of chemical reactions for the home lab is actually a sub-set of a larger question that is more appropriate for the computational section of this forum, so I will take it there.

If anyone reads this and happens to have a list of chemical reactions for the home lab they could share I would be very appreciative! Thanks, and please see my other post in the computational section if you happen to know of larger rxn lists available somewhere.




“If we knew what it was we were doing, it would not be called research, would it?”

-Albert Einstein
View user's profile View All Posts By User
chemrox
International Hazard
*****




Posts: 2928
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: psychedelic

[*] posted on 24-1-2013 at 17:56


Quote: Originally posted by kavu  
I would tweak the list of solvents a bit. Most used solvents in (organic) chemistry lab are hexane, ethyl acetate and DCM. An important consideration in starting a home lab is the waste management. How and where to dispose halogenated solvent waste, heavy metal waste and so forth.


Well said. I like the list except for the solvents. There's no getting around proper waste disposal. When I was an undergraduate chemistry student there was an outside dump. As a project I sampled a downgradient pond and found it full of halogenated crap. Today I bite the bullet and carry my waste to the garbage contractor who logs it in for eventual incineration. I am a "conditionally exempt small quantity generator." Others might be able to pay a company that has a regular waste stream to carry a bit extra. Since we pay by weight it behooves us to minimize and go green where possible. This is a good thing.




"Ignorance is the Mother of Devotion." — Robert Burton.
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 25-1-2013 at 08:42


So are you suggesting ditching the DCM and chloroform from the list and adding ethyl acetate? I guess beginners may not know how to dispose of chlorinated solvents properly. Handling these solvents is also a pain I guess; I'll put asterisks next to these.

I know waste generation, minimisation, and neutralisation is essential for any home lab, especially when groundwater is involved. I personally much prefer diethyl ether, methanol and ethanol for extractions than chlorinated solvents. I didn't put Et2O because it can be difficult to obtain and easier to synthesise than to buy.

Any further suggestions for the list of solvents? I was hesitant about including toluene and xylene, but these hydrocarbons can be used for reactions in addition to solvation.




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
zenosx
Hazard to Others
***




Posts: 188
Registered: 7-7-2012
Location: East TN / Near Oak Ridge
Member Is Offline

Mood: Awaiting Results....

[*] posted on 5-2-2013 at 20:26


I have most of whats on the list, and unless I missed it, one of the #1 things a home chemist (or pro for that matter) will need is an extensive array of cleaning brushes and such. The first time you try to clean a test-tube without a proper brush will leave you aggravated to say the least.



A question that sometimes drives me hazy: am I or are the others crazy?

Albert Einstein
View user's profile Visit user's homepage View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 6-2-2013 at 12:49


Yes, brushes come in handy. I should have also included test tubes and well plates in the list. The large test tubes come in really handy. Small test tubes are just unnecessarily irritating.

[edit] I may also add a digital multimeter and assorted thermocouples to the list. Those are also a tremendous help when working with high temperatures.

[Edited on 2-6-2013 by White Yeti]




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
kadriver
Hazard to Others
***




Posts: 196
Registered: 7-11-2012
Location: United States
Member Is Offline

Mood: Thankful

[*] posted on 18-2-2013 at 21:22


I have several test tube brushes with metal handles.

They get real rusty after a few uses.

Is there such a thing as a nylon handled test tube brush with nylon bristles?

Thanks, kadriver
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 21-2-2013 at 13:04


You could try galvanizing the handle. It's not the most glamorous solution, but it will work if done correctly. All you need is a zinc solution and a zinc anode. Make sure to thoroughly clean the surface of the handle, perhaps by immersing in vinegar.

I use paper towels and a skewer to clean test tubes, none of that fancy equipment you people keep mentioning:P




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
Hexavalent
International Hazard
*****




Posts: 1564
Registered: 29-12-2011
Location: Wales, UK
Member Is Offline

Mood: Pericyclic

[*] posted on 21-2-2013 at 13:48


Quote: Originally posted by kadriver  

Is there such a thing as a nylon handled test tube brush with nylon bristles?


Yes there is, and I have one :P

Scrub brushes suitable for chemistry can often be found with baby supplies, meant to clean out bottles when they're washed and sterilised.




"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
View user's profile View All Posts By User
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
*****




Posts: 1986
Registered: 2-3-2011
Member Is Offline

Mood: No Mood

[*] posted on 21-2-2013 at 14:14


In terms of reagents, I think the best thing to do is to buy them specifically as you need them. And hold on to it, even after your experiment when you think you will probably never use it again. I have been surprised many times years later when I learn more about chemistry and went to perform a new experiment, often the experiment requires some strange compound which I had thought I would never have any use for ever again.

Which compounds to buy also depends much on what type of chemistry you think you will be focusing on.
View user's profile Visit user's homepage View All Posts By User
woelen
Super Administrator
*********




Posts: 7466
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 22-2-2013 at 01:45


I have written a webpage about setting up a home lab for inorganic chemistry experiments. It covers the purchase of basic equipment and what chemicals one can start with.

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




The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
Steve_hi
Hazard to Others
***




Posts: 196
Registered: 4-12-2010
Member Is Offline

Mood: No Mood

[*] posted on 24-2-2013 at 14:13


In the list chemical for the basic lab the salts of sodium and potassium is it a good idea to have both cations of these compounds or can either be used

[Edited on 24-2-2013 by Steve_hi]
View user's profile View All Posts By User
Hexavalent
International Hazard
*****




Posts: 1564
Registered: 29-12-2011
Location: Wales, UK
Member Is Offline

Mood: Pericyclic

[*] posted on 24-2-2013 at 14:25


Having both won't hurt, but it is usually unnecessary as they are often interchangeable.



"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
View user's profile View All Posts By User

  Go To Top