Sciencemadness Discussion Board

What could Benzene be worth, sold by the liter.

nannah - 17-6-2014 at 10:12

Hi, guys. :) I would like to ask you a question. I will give a little bit backround first. I was talking to a new neighbour today, and we were talking about everything. Art, furniture, and all of a sudden he said he had 5 liters of Benzene in the house that he wanted to sell. He said that it was worth 2000-2500 £ but that figure seem a bit too high to me.
Isn't it?

Praxichys - 17-6-2014 at 10:59

That figure is not even close!

Sigma sells benzene at $403 USD (about £238) for 6 liters.

Unless it's some super special high purity benzene, (at which point one would wonder why there are 5 liters of it) or some sort of antique, there is absolutely no way it costs that much.

Nicodem - 17-6-2014 at 11:14

The price of benzene is less than 2 $/kg for bulk purchases.

plante1999 - 17-6-2014 at 12:13

Benzene is quite a cheap industrial chemical, but for the chemist, a 25-50$ per L is considered fine, and 100$/L if costly.

Dr.Bob - 17-6-2014 at 12:16

Benzene is a byproduct of the petroleum industry. It would be slightly higher than gasoline per gallon or L, as they actually don't want in in gasoline due to the environmental and OSHA issues. But is is harder and harder to find lately. Toluene is not hard to find, and works just as well for many tasks.

We used to put surplus benzene and similar hydrocarbons into the truck gas tank we used at the chemical place that I worked at many years back.

jock88 - 17-6-2014 at 14:39


Depends on purity. If selling stuff that is research grade (99.99 or whatever) then it's going to be expensive.

FireLion3 - 17-6-2014 at 14:47

There are several chemical supply companies in the USA that sell Benzene. Here is a rough list of prices I have encountered for Reagent ACS grade:

500mL $60
4L $230
4Lx4 $700
20L $800-1100
200L $2600-3200


Don't really need any licenses or anything like that for any quantity of purchase. Laws may be different in the EU

nannah - 17-6-2014 at 19:54

He told me that he had it for a few years, so i want to test the purity and clean it up. Preferabley, in the easiest possible way.

woelen - 17-6-2014 at 22:36

I can buy general lab reagent grade benzene for appr. EUR 25 per liter (and I did so).

nannah - 18-6-2014 at 03:22

Quote: Originally posted by woelen  
I can buy general lab reagent grade benzene for appr. EUR 25 per liter (and I did so).


So you don't think i should pay more then 125 $ for the 5 liters?
I think he was messing with me. :)

Anybody know a good way to determinate purity. He said that its been standing there for years, maybe they have kind of expiration date?

Thanx for all your help. /N.

woelen - 18-6-2014 at 04:36

If stored properly (clean glass bottle, good cap, well sealed), benzene has no expiration date. Even after tens of years of storage it still is perfect.

For 5 liters a price of $125 (appr. EUR 100) is decent, provided it still is pure. Industrial grade benzene is cheaper, but it also is not as pure as reagent grade benzene.

plastics - 18-6-2014 at 11:51

Sigma-Aldrich ReagentPlus > 99% =£27.12 for 2.5L inc tax

nannah - 5-7-2014 at 03:45

I told him that the price he first gave me was ludacris, and i think he are willing to discuss a new number.
I just want to know if i were to buy it, that it is of a good grade. And also that it really is benzene.

I am going to ask for a small sample that i can test, but i am not sure how.
I know the bp, so i can know for sure that it is the real deal. But how do i meashure the amount of water and other impurities it holds?

Thanks in advance guys. :)

unionised - 5-7-2014 at 04:26

I'd check the melting point.
Put some in a test tube and surround it with ice and water.
Anything that doesn't freeze isn't benzene.
If essentially all of it freezes that would suggest it's fairly clean- "commercially pure" benzene.

Also, this is a simple way of purification.
Cool the stuff until 90% or so has frozen, then pour of the liquid.
Almost all the impurities will be in the liquid so, when the frozen stuff melts, it will be of very high purity.
(You can repeat this with the 10% that you poured off and that way you should recover nearly 99% of the original material in a pretty pure form. assuming it wasn't too heavily contaminated in the first place.)
The big advantage of freezing as a method of purification is that it avoids having lots of boiling flammable liquid.
According to this
http://www.ncbi.nlm.nih.gov/pubmed/18960430
the solubility of water in benzene is only 0.0363M: about 0.07%
That won't matter for most purposes and it's easy to remove by distillation.
(unexpectedly, perhaps, the water distills off first as an azeotrope).

aga - 5-7-2014 at 08:00

what ?!?!
Benzene, bp 80.1c, water bp 100C and the azeotrope comes over FIRST ?

Would never have expected that !

nannah - 5-7-2014 at 08:14

Quote: Originally posted by unionised  
I'd check the melting point.
Put some in a test tube and surround it with ice and water.
Anything that doesn't freeze isn't benzene.
If essentially all of it freezes that would suggest it's fairly clean- "commercially pure" benzene.

Also, this is a simple way of purification.
Cool the stuff until 90% or so has frozen, then pour of the liquid.
Almost all the impurities will be in the liquid so, when the frozen stuff melts, it will be of very high purity.
(You can repeat this with the 10% that you poured off and that way you should recover nearly 99% of the original material in a pretty pure form. assuming it wasn't too heavily contaminated in the first place.)
The big advantage of freezing as a method of purification is that it avoids having lots of boiling flammable liquid.
According to this
http://www.ncbi.nlm.nih.gov/pubmed/18960430
the solubility of water in benzene is only 0.0363M: about 0.07%
That won't matter for most purposes and it's easy to remove by distillation.
(unexpectedly, perhaps, the water distills off first as an azeotrope).


Thanks for taking your time to helping me out. Your post have been really helpful. I really appreciate it. :)

unionised - 5-7-2014 at 11:29

Quote: Originally posted by aga  
what ?!?!
Benzene, bp 80.1c, water bp 100C and the azeotrope comes over FIRST ?

Would never have expected that !

I think it's pretty much guaranteed with two immiscible liquids.
http://en.wikipedia.org/wiki/Heteroazeotrope