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tito-o-mac
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Chemistry equipment
Hello there all. I was just thinking of the basic equipment, apparatus and chemicals needed for a beginner to start up as most of us do not have easy
access to labs. Any suggestions/comments etc? For example, the number , type of flasks neded, beakers, heating equipment, chemicals, safety gear etc.
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12AX7
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Jars of canned food are a good source for soda-lime (DO NOT HEAT!) "beakers". Merely divert the flow to your glass recycling bin.
Number? More.
Some sort of heat is good...a microwave works in a pinch, and can be used (carefully) with soda-lime glass. You need pyrex or metal to use electric
or fire though.
If you want to do anything somewhat more interesting, you'll want a distillation column. Essentially required for much organic prep.
Tim
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Elttil
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You should ware safety goggles when you work with fire and reactions. When you work with dusting salts you should ware a dust mask.
For chemicals I would recommend some acids (such as hydrochloric) and some sodium or potassium salts.
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Slimz
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i have started buying from here
www.agile-fx.com
They are cheap and the customer service is great...
[Edited on 18-9-2007 by Slimz]
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Armistice19
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Problem
I have attempted to use Pyrex for heating solutions about 4 times now. The first time I did this I was boiling a solution of Sodium Hydroxide on a
laboratory "Hot Plate" from my school. As the solution boiled, and crystals began to form at the bottom, once this happened I decided to add more
sodium hydroxide solution on top of this anhydrate to get more overall yield. As I did this, and as soon as the room temperature water touched the hot
Pyrex glass, it immediately shattered spraying sodium hydroxide everywhere, and destroying my hotplate with bright and loud flashes of electricity and
the steaming of dead blown circuits. After this I decided to boil some water on my stove with Pyrex just to see what would happen. I filled the glass
halfway full of tap water, and put the flame on as low as it would go, then I kept my distance and watched. KABLAM! The gas flames were put out by the
splashing water and shards of glass flew all over my kitchen. This happened on 2 other occasions, and I just don't understand. I was told that Pyrex
could withstand extreme temperature changes without shattering. I need this Pyrex because I can't have a metal container that will be easily oxidized
by boiling bleach, Nitric, or Sulfuric Acids. Sure I could go out and buy a stainless steel pot, or use an old tuna can, but I'm not interested in
that yet, first I want to know why people say this Pyrex won't shatter when in fact it does. Has this happened to anyone else? Perhaps the Pyrex can
only withstand so much temperature change before shattering? Whatever it may be, even if it is my own fault, I would like to know what is going on
here.
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Slimz
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FIRST of all NEVER let pyrex TOUCH the heat source like a hotplate... ALWAYS have airspace (or water).. touching a flame is OK (as long ast the
mixture is not flamable  ) i have sometimes used a frying pan with water in it
(about an inch or so) as a buffer for my pyrex...
----- Pyrex -----
----- Air/water-----
------heat source-----
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chromium
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Do not expect that pyrex (or any other sort of glassware) will withstand everything. Always try to make temperature changes as smooth as possible.
Some years ago i routinely boiled liquids on propane flame. It did not break my pyrex but some of rather precious glassware was ringing with alarming
sound if flames were big and uneven.
Now i use air bath. Its easy - just place empty stainless steel pot on hotplate and fix flask inside it but without any contact with hot surfaces. You
can even do it without pot - just fix flask 1...2cm above hotplate. This way i can easily heat to about 200C. For higher temperatures i use gas flame
and if possible prefer small flasks or test tubes.
Its desirable that flame never gets in contact with glass. You can easily make wide tube from sheet metal (or from tin can) to direct most of heat to
your flask even if flame ends 10 or 20cm below the flask.
[Edited on 18-9-2007 by chromium]
When all think alike, then no one is thinking. - Walter Lippmann
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12AX7
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I've found I can put pyrex (at least relatively thin RBFs) in contact with the fat end of a rich flame.
Edit: I might add that my all purpose propane torch, which serves me from boiling water to brazing steel to melting whole crucibles of bronze, gives a
flame much more diffuse than, say, a bunsen burner, which is about half the diameter of this torch. I have complete control over the mixture, and it
burns stable down to suprisingly low pressures (fractional PSI), allowing me to set up a slow, diffuse flame.
Tim
[Edited on 9-18-2007 by 12AX7]
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Eclectic
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Also "Pyrex" is a brand name which no longer has any relationship to Corning when it comes to houseware glass items. These may no longer actually be
made of borosilicate glass. I've many "Pyrex" measuring cups and other household glass items break from thermal stress in the last 5 years. The
thicker glass is also not as resistant to thermal stress breakage as thin laboratory glassware.
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Slimz
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I'm in communications with the guy from www.agile-fx.com trying to convince him to put together some kits.. they have very good prices.. a $100 set would pretty much include ALL the
basics including separator, distiller etc...
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Elttil
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www.agile-fx.com seems to be a nice page with good prices. Personally I have ordered a scale from ebay  . I'll tell you later about quality..
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Slimz
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I know he also sells on ebay..
the prices are the same on his site tho.. some of the glassware is used but in fine condition.
i realy dont mind used glassware as long as the condition is good...
Johnny was a chemist’s son, but now he is no more. What Johnny thought was H2O was H2SO4
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Slimz
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WOW ! !
I just found out that DC Scientific glass is one of our clients... (we are tere IT staff)
Bet i could get some deals from them...
Johnny was a chemist’s son, but now he is no more. What Johnny thought was H2O was H2SO4
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hdcwr0x2
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Wanted to say thanks for posting agile-fx, I live in Houston when not at college and even though they're not exactly in Houston, at least shipping
should be quick.
When I start building my collection, should I get a straight through condenser or spend a little more and buy a Graham? I'm just going to be doing
some simple organic fractional stuff and maybe some acid purifications etc, but I'm thinking Graham.
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evil_lurker
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I (meaning my business Volunteer Scientific, Inc.) have accounts with Wilmad, Ace Glass, and Chemglass.
If you got the $'s I can get you anything you want... just be advised that it will cost a little bit over published retail prices. This is because my
business is not set up as a reseller with these vendors and as such can't get the items drop shipped. In addition, since I don't purchase thousands of
dollars worth of glass at a time, I can't get a deep discount.
And to hdcwr0x2, don't get a graham on a simple distillation setup. They are primarly used in the vertical position, and when working horizontally the
distillate will pool up in the coils. A 300mm liebig will easily take care of most things that one will encounter.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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SecretSquirrel
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I always had the impression that Graham condenser is used for cooling of the distillate only. Because as Evil_lurker said the condensed vapors get
stuck in the coils and you'll have a hard time getting the stuff out.
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Sauron
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Grahan condensers are for vacuum distillations, they serve to increase the dwell time of the vapo in the coundenser, and it would be a mistake to try
to use one for reflux.
Whereas if you use a Liebig for vacuum distillation you may find that some vapor makes it through, hopefully to get condensed in your cold trap.
The use of some more efficient condenser designs will resolve the problem. A good long West for example is much better than a Liebig. Allihn and
Friedrichs and double-surface condensers with cold coil (rather the reverse of a Graham) are mainly for reflux but in some instances can be used
conventionally. Allihm condensers need to be vertical whether reflux or delivery as otherwise some condensate will be held up from fraction to
fraction.
As for Graham, there's a pressure drop across a Graham. See for yourself.
Sic gorgeamus a los subjectatus nunc.
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chemkid
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i buy from http://www.hometrainingtools.com/
chemkid
[Edited on 1-10-2007 by chemkid]
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djcubis2003
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When using a heating mantle is it nessesary to leave an air bath or just let it sit in the mantle to avoid breakage.
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Slimz
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| Quote: | Originally posted by hdcwr0x2
Wanted to say thanks for posting agile-fx, I live in Houston when not at college and even though they're not exactly in Houston, at least shipping
should be quick.
When I start building my collection, should I get a straight through condenser or spend a little more and buy a Graham? I'm just going to be doing
some simple organic fractional stuff and maybe some acid purifications etc, but I'm thinking Graham. |
Excelent... If there is one thing I AM good at its finding deals online... It's kinda funny, them being in texas and all...
Johnny was a chemist’s son, but now he is no more. What Johnny thought was H2O was H2SO4
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Fitz
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Another good site is http://www.sciplus.com They have some nice Pyrex knockoffs.
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Antwain
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I have a type of condenser which I can't identify. It seems to share properties of both Graham and Dimroth condensers. It was a water jacket and a
spiral. These are joined at the bottom, so that the inlet and outlet are at the top. I am guessing that water is meant to go down the jacket then up
the spiral, since that way it would still be cold, unlike the reverse, where the jacket would provide little assistance. Can anyone clear this up and
tell me the primary use of this condenser?
Since I also have a couple of air and libeig condensers as well as a graham, I haven't used it, but it would be good to know what it is for.
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not_important
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| Quote: | Originally posted by Antwain
I have a type of condenser which I can't identify. It seems to share properties of both Graham and Dimroth condensers. It was a water jacket and a
spiral. These are joined at the bottom, so that the inlet and outlet are at the top. I am guessing that water is meant to go down the jacket then up
the spiral, since that way it would still be cold, unlike the reverse, where the jacket would provide little assistance. Can anyone clear this up and
tell me the primary use of this condenser? |
Look like any of these?
http://www.sigmaaldrich.com/Area_of_Interest/Equipment_Suppl...
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Antwain
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It is closest to the one called "Aldrich jacketed Friedrichs coil condensers", however The jacket is straight like on a liebig condenser. Funny how
they show the coil as the "in" and the jacket as the "out". Doesn't seem right to me.
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Armistice19
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When it comes to buying lab equipment, what other options do we have? I was wondering if maybe anyone had any cool ideas on how to improvise these
various chemistry equipments. Now I don't usually view myself as a chemist in search of the "poor man's" method to an easy way in, but I always ask
myself, why pay for something when you don't have to? When it all boils down to it, my excuse for being the way I am is just the fact that I would
rather be a MacGyver than an Einstein I guess. I mean yes I have the money for material conveniences, but it has always been so much more fascinating
a concept for me to be able to walk into an office building, observe my surroundings, and list in my mind the endless possibilities that modern
society provides for me in the realm of explosives, and with nothing but the clothes on my back I would say to myself "I can make dynamite right now."
Even the simple over the counter items at your local K-mart are of more interest to me than reading a magazine full of products by Fisher Scientific,
and they cost significantly less too. Just looking at what is allowed by law to be sold in our stores, and then comparing it with each products
potential risk for danger when it is used in the right context by an informed individual. I mean just look at Health Salt for example, or Aluminum
foil, or even Christmas lights. These stupid everyday household items and uselessly abundant corporate products become exactly what they are not,
useful, and it is because of this that we can be so sure that we are informed of what so many others are not. We can finally realize that all the
things that we can’t obtain, and all the things that we can never find, are obtainable, right under our noses. The only thing that’s stopping us
from reaching out and taking them is our lack of knowledge. In today’s world we have become so dependent on pointless technological advancements and
American appliances for the lazy lifestyle. If we were to loose our methane we would assume that we couldn't cook food until we got it back, or even
keep warm without a working furnace. If we don't have electric light bulbs we think we can't see, if we don't have digital alarm clocks we think we
can't tell what time it is, and if we don't have coffee machines.... we think we can't drink coffee. Maybe one day you stopped to think about poverty,
and realized that if someone can’t pay their electricity bill, the only thing that’s stopping them from gaining back their access to fresh food,
communication, and lighting is the fact that they don't know enough about electricity and wiring to reconnect it themselves? Even if it was the middle
of the night and they had absolutely no way of obtaining a flame, flashlight, or batteries, they could just mix Chili powder and bleach, with any
common alkali, and a couple drops of antiseptic from a medicine cabinet when added to the mixture would create chemiluminescence that would last 5
times longer than any flame or candle, and at no expense to you. How about the fact that we rely on automobiles for transportation, and if our car
battery runs out we think we have to buy a new one for $60 when we could just use garden sulfur, water, and a brazing kit from home depot to make
enough battery acid to refill it ten more times? Why should we allow ourselves to be bound by these tethers and weights when we can just cut right
through them? What are we, as an informed and creative community, really capable of in the field of chemistry? What can we really do with what we
already have? What can you create with the contents of your home?
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