9 ms·

Benzene at 200

238 points by Brajeshwar 1y ago

neuroelectron 1y ago
[flagged]
kccqzy 1y ago
> Its peculiar behaviour, such as its surprising stability despite being highly unsaturated, hinted at a deeper mystery that would not be fully resolved until the mid-19th century with the proposal of its cyclic structure. How were chemists in the early 19th century able to determine benzene must be highly unsaturated without knowing its structure? Did they simply combust it and measure the amount of water vapor and carbon dioxide produced?
- deleted 1y ago
  [deleted]
- perihelions 1y ago
  I think you're right, https://en.wikipedia.org/wiki/Kaliapparat https://en.wikipedia.org/wiki/Kaliapparat
  - sndean 1y ago
    Yeah an apparatus like that and work out that benzene had a very different carbon dioxide to water ratio than something like hexane.
  - chermi 1y ago
    How cool, it's still in the ACS logo! Germans have the best names lol. Calibration apparatus.
    - namibj 1y ago
      No, it's from al kali ne.
    - perihelions 1y ago
      > "Calibration apparatus" I believe it's kali from German Kaliumhydroxid[0] (KOH, what it uses to dissolve CO2), from the same "potassium" root as al-kali in English, from medieval Arabic[1]. (And also metonymically a name for the coastal salt-marsh plant[2] from which medieval workers sourced potash/potassium[3]. I actually submitted that plant to HN [4] a few days ago, but no one was excited about it. They were once an essential ingredient in glassmaking, hence their other name, "glasswort"). [0] https://de.wikipedia.org/wiki/Kaliumhydroxid https://de.wikipedia.org/wiki/Kaliumhydroxid [1] https://en.wiktionary.org/wiki/kali#English https://en.wiktionary.org/wiki/kali#English [2] https://en.wikipedia.org/wiki/Salsola_kali https://en.wikipedia.org/wiki/Salsola_kali [3] https://en.wikipedia.org/wiki/Potash#History https://en.wikipedia.org/wiki/Potash#History [4] https://news.ycombinator.com/item?id=44128748 https://news.ycombinator.com/item?id=44128748
      - ahartmetz 1y ago
        The literal meaning is indeed potassium apparatus / device / contraption. The Kali part is indeed shortened from Kaliumhydroxid. Strangely enough, the modern German name is Fünf-Kugel-Apparat, "five balls apparatus". I found that one simply by going through "Other languages" on Wikipedia. And benzene is called Benzol in German. And gasoline is called Benzin - that word has false friend potential because it seems more similar to benzene. It is also not derived from the name of Carl Benz of Mercedes-Benz fame who used it in the first practical automobile that he invented.
- isoprophlex 1y ago
  What these early chemists accomplished with, to our eyes, extremely crude methods is astounding. Physical methods like weighing, burning and collecting residue; describing crystallization and precipitation behavior, even smelling (and sometimes tasting) was at one point a routine thing to do.
  - deleted 1y ago
    [deleted]
  - radicalbyte 1y ago
    The story of how Oxygen was discovered was super interesting and involved all of these methods.
    - bravesoul2 1y ago
      Wow. Pre that discovery what did they think explained phonomenon like snuffing out a candle. Or blowing air on a fire.
      - bruckie 1y ago
        https://en.wikipedia.org/wiki/Phlogiston_theory https://en.wikipedia.org/wiki/Phlogiston_theory
    - implements 1y ago
      Argon is an interesting one. A comparison between chemically synthesised nitrogen and ‘pure’ nitrogen extracted from the air (with the oxygen, carbon dioxide and water removed) revealed a discrepancy: https://en.wikipedia.org/wiki/Argon#History https://en.wikipedia.org/wiki/Argon#History https://www.youtube.com/watch?v=loqudG71uBM https://www.youtube.com/watch?v=loqudG71uBM (Chemistorian, noble gases)
- Horffupolde 1y ago
  Yes.
- jcranmer 1y ago
  There's a two step-process to stochiometry. The first step, as people have elaborated below, is combust the compound and measure the weights of various oxides, which (after the atomic masses of the relevant elements were settled around the 1820s) lets you work out the empirical formula of an unknown molecule. For benzene, this would tell you that there is 1 C : 1 H, but this doesn't tell you if it's C₄H₄ or C₆H₆ or C₁₁₁H₁₁₁. The second step is to determine the molar mass of your compound, which requires finding something that depends on the amount of substance but not the mass directly. (In modern times, this is primarily mass spec). Back in the 19th century, this is probably abusing the ideal gas law, which lets you compute the number of moles in a gas given the pressure, temperature, and volume of a vessel. Combine this with the mass of that container, and you know how much a mole weighs. If you get out, say, 77g/mol, and you know that the ratio is 1 C : 1 H, well, the only formula that makes sense is C₆H₆ (which should ideally have 78g/mol, but you might not get the right answer for various experimental reasons).
Brajeshwar 1y ago
I realize the article is asking for a login (a free account). Here is the Archived link https://archive.is/X1iHZ https://archive.is/X1iHZ
AStonesThrow 1y ago
[dead]
chasil 1y ago
"...benzene holds a special place in education. Generations of high school and university students have been introduced to the elegance of its structure and the profound mystery surrounding its stability." Admire it from a distance. "Benzene is classified as a carcinogen, which increases the risk of cancer and other illnesses, and is also a notorious cause of bone marrow failure. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, bone marrow abnormalities and cardiovascular disease. "...There is no safe exposure level; even tiny amounts can cause harm." https://en.wikipedia.org/wiki/Benzene#Health_effects https://en.wikipedia.org/wiki/Benzene#Health_effects
- aszantu 1y ago
  Lots of sunscreen and other beauty products seem to be contaminated with benzene. Johnson & Johnson was caught a few times putting it in baby powder or something
  - dylan604 1y ago
    J&J's baby powder situation was related to asbestos[0]. So it must be under your "or something" hand wavy qualifier. If you're going to sling dirt, at least make it accurate. The benzene use was in other products like sunscreen[1] [0]https://www.reuters.com/investigates/special-report/johnsonandjohnson-cancer/ https://www.reuters.com/investigates/special-report/johnsona... [1]https://www.jnj.com/media-center/press-releases/johnson-johnson-consumer-inc-issues-voluntary-recall-of-specific-neutrogena-and-aveeno-aerosol-sunscreen-products-due-to-the-presence-of-benzene https://www.jnj.com/media-center/press-releases/johnson-john...
    - bee_rider 1y ago
      They mention the sunscreen in the other sentence of the post. I gotta say, your post comes off (maybe I’m misreading it) as a bit critical, given that you seem to agree with the other poster as to the underlying problem (frequent contamination issues).
_WhySoSerious_ 1y ago
Kekule who dreamt of 6 serpents each eating others tail and discovered the hexavalent structure, meanwhile cries in a corner. No mention of Kekule in the article.
- carbocation 1y ago
  This does seem like an important omission.
- JKCalhoun 1y ago
  Agree: https://en.wikipedia.org/wiki/August_Kekulé#Kekulé's_dream https://en.wikipedia.org/wiki/August_Kekulé#Kekulé's_dream (I had the impression from somewhere else that his "reverie or day-dream" might have instead been a pipe dream — as in the literal pipe dream (opium?). But I can now find nothing to substantiate this at all so, maybe just ignore.) EDIT: perhaps I was reading too much into this page from the Golden Book of Chemistry: https://www.slideshare.net/slideshow/the-golden-book-of-chemistry-experiments/3491280#81 https://www.slideshare.net/slideshow/the-golden-book-of-chem...
- FlyingSnake 1y ago
  Omitting such an important story from the article feels sloppy. For me, no other story from Chemistry is as fascinating as Kekule dreaming up Benzene’s molecular structure. An important reminder to me about the power of narrative and storytelling.
- epiccoleman 1y ago
  For a tangent on Kekule, I really enjoyed Cormac McCarthy's essay The Kekule Problem - published in 2017 and apparently his first published work of non-fiction.
  - jihadjihad 1y ago
    Link to essay: https://nautil.us/the-kekul-problem-236574/ https://nautil.us/the-kekul-problem-236574/
    - 1y ago
vondur 1y ago
I've read that back in the day chemists used to nearly bathe in this stuff. Now it's rarely used in instructional chem labs. Heck as an undergrad in the 90's we were using Potassium Dichromate as an oxidizer. I spilled some on me and it ate through my lab coat and shirt beneath it. Probably should have had an apron on too...
andygeorge 1y ago
I was a kid when there was a Benzene spill up where I lived at the time (Duluth, MN). I remember having to evacuate to our aunt's house out of town. My dad stayed at home doing yardwork until he felt "a little lightheaded" and finally joined us. https://en.wikipedia.org/wiki/1992_Nemadji_River_train_derailment https://en.wikipedia.org/wiki/1992_Nemadji_River_train_derai...
- ThrowawayTestr 1y ago
  Benzene is really bad for you
scottlawson 1y ago
I love articles like this that give the context and history to important but not often talked about molecules. I enjoyed this as much as the "chemicals I will never work with" series.
jasonthorsness 1y ago
Seattle’s Gas Works Park has some strange equipment to address the benzene contamination. Bold move to make industrial sites into parks (it is one of the best in Seattle though!) Edit: better link https://apps.ecology.wa.gov/cleanupsearch/site/2876 https://apps.ecology.wa.gov/cleanupsearch/site/2876 Original link was older 2005 report: https://apps.ecology.wa.gov/cleanupsearch/document/1509 https://apps.ecology.wa.gov/cleanupsearch/document/1509
- robocat 1y ago
  Relevant sections from the 2005 report: 3.1 Benzene. On the east side of the Park, south of the Play Barn the groundwater is contaminated with benzene. An interim action removed a benzene containing LNAPL that had been discovered during site investigation. The remedy chosen for benzene was an air-sparging/soil vapor extraction (AS/SVE). The AS/SVE system covers approximately 1.5 acres of the Park. It is unnoticeable to Park users except for a small equipment box near the Towers. . An action level was calculated based on MTCA Method B surface water criteria and a dilution attenuation factor (DAF). The calculation used to set the DAF and the action level for benzene is given in appendix 1. 4.1 Benzene. Benzene concentration in the compliance well OBS-1 remains below the action level but above the method B groundwater cleanup level. The remedy, therefore, remains effective. See figure 3 below.
divbzero 1y ago
It amazes me that the same person who discovered benzene also discovered electromagnetic induction and Faraday’s laws of electrolysis.
- ipdashc 1y ago
  > and Faraday’s laws of electrolysis Wow, what are the chances he discovers something with a name like that?
- nanna 1y ago
  And wasn't Faraday also a self-taught amateur whose maths was so poor that he couldn't even do trigonometry? A beacon of hope for those of us without doctorates in physics out here...
  - Qem 1y ago
    He was lucky being born when there was still a lot of low hanging fruit lying around.
groos 1y ago
I once pulled on a glass pipette too hard and got benzene in my mouth. This was 36 years ago, still doing well :-)
joloooo 1y ago
Interesting article. I have always viewed Benzene as a bogeyman of sorts. My parents both interacted with it often throughout my life. My dad was a chemical engineer for an oil company, and he often spoke of spills and incidents. As a kid, I never understood what it was, but the tone and urgency were always something scary. I also strongly suspect my mother's Benzene exposures (nurse cleaning lab slides with Benzene and no PPE) led to me battling Langerhans Histiocytosis throughout my childhood. https://en.wikipedia.org/wiki/Langerhans_cell_histiocytosis https://en.wikipedia.org/wiki/Langerhans_cell_histiocytosis
- jordanb 1y ago
  "Benzene is what anti-nuclear people think nuclear waste is."
quietbritishjim 1y ago
I'll admit I know very little chemistry, but I think the article would've been much better for people like me of it included any specific examples at all of benzene uses. It's filled with assurances that it's important and used all over the place but I didn't find that very enlightening.
- philipkglass 1y ago
  https://en.wikipedia.org/wiki/Benzene#Uses https://en.wikipedia.org/wiki/Benzene#Uses Benzene is used mainly as an intermediate to make other chemicals, above all ethylbenzene (and other alkylbenzenes), cumene, cyclohexane, and nitrobenzene. More than half of the entire benzene production is processed into ethylbenzene, a precursor to styrene, which is used to make polymers and plastics like polystyrene. Some 20% of the benzene production is used to manufacture cumene, which is needed to produce phenol and acetone for resins and adhesives. Cyclohexane consumes around 10% of the world's benzene production; it is primarily used in the manufacture of nylon fibers, which are processed into textiles and engineering plastics. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives, and pesticides. It's an important feedstock in the chemical industry but it is no longer used directly in household products. It used to be common in solvent/glue/grease remover formulations before the health hazard was widely appreciated.
- andrewflnr 1y ago
  It's kind of hard to explain how widespread a usage like "solvent" is. A huge amount of chemical reactions are most convenient to do in a liquid, a liquid that can dissolve the materials you're working with. That's a solvent. Benzene can dissolve a lot of things, including some that are really hard to dissolve otherwise. So it can be used for a huge variety of reactions, but as the sort background player that you might not pay attention to unless you can't have it. It's a little like asking "what are the uses of water in chemistry", where you're tempted to answer, "um, everything?" Not quite, but not that far off either. (And with more cancer of course.) Edit: disclaimer, I'm not a chemist, just an interested layman.
  - deleted 1y ago
trebligdivad 1y ago
The article talks about the wonders of bucky balls and nanotubes - does anyone know what useful stuff has come out of those yet? I think I heard there's some work on nanotubes coming up on transistors in the next gen of chips? Not sure what bucky balls and other fullerenes are being used for? (I remember originally there was talk of lubricants?)
- bell-cot 1y ago
  > does anyone know what useful stuff has come out of those yet? Quip: Every chemical researcher's #1 need is for research funding, no?
- lightedman 1y ago
  For useful carbon nanotubes, look no further than nanotape. That shit is extremely strong and will happily peel the paint or wallpaper from your walls.
euroderf 1y ago
Benzene must've been examined down to the nth degree in quantum analysis. Maybe there's an article ?
- toddm 1y ago
  Lots of them. I wrote 6 on my way to my Ph.D. in the late 1990s, and there was plenty of prior art at that time. Here's one of mine, see references therein as well: https://pubs.aip.org/aip/jcp/article-abstract/110/7/3326/475549/Quantum-dynamics-of-overtone-relaxation-in-30-mode https://pubs.aip.org/aip/jcp/article-abstract/110/7/3326/475...
jabl 1y ago
I remember in high school chemistry (or physics?) we had a wooden model of the benzene ring with the ground state molecular orbitals. Diameter about 30cm.
k__ 1y ago
I did an internship at a chemical laboratory once. The older folks told me that they aren't allowed to use the awesome stuff anymore. Back in the days, they would use Benzene for everything, the only stuff that would get the lab floors clean at the end of the day. Same with asbestos, leaded fuel, and whatnot. Compounds that are perfect for their use cases, yet highly toxic.
- pumnikol 1y ago
  One of my elderly colleagues once told me that at the end of each day, they'd put all the lab coats in a big vat of benzene to clean them. The next day, they took them out, let them dry for a short while and then just put them on again. I think it was in the early 80s? He did develop cancer later.
- fuzzfactor 1y ago
  This was the traditional solvent for cleaning up and removing excess ink in print shops all over the place. Often still known by its archaic name Benzol when I was growing up. In high school, walking by the student print shop you could smell it way down the hall at all times. The chem labs were not nearly as bad because they had better ventilation to begin with. Plus before my time benzene had also been prized as high-octane motor fuel for early cars back when it was obtained for sale naturally by removal from aromatic crude oils in some refineries. This was not such pure benzene however the significant percentage of impurities at the dispenser acted with an "antifreeze" effect and it handled no differently than regular gasoline below 32 degrees F. Pure benzene freezes at about 40 degrees F, and that pure of a hydrocarbon ended up being too expensive to burn anyway. IIRC it can really make a lawn mower cut taller grass than premium gasoline, and scientifically it does have about 100 antiknock rating so it's no surprise.
  - k__ 1y ago
    "Often still known by its archaic name Benzol" In German, that's the regular name, haha.
    - chasil 1y ago
timthorn 1y ago
The Royal Institution, where Faraday first isolated Benzene, is celebrating with a Discourse next month: https://www.rigb.org/whats-on/discourse-celebrating-200-years-benzene-whale-oil-aromaticity https://www.rigb.org/whats-on/discourse-celebrating-200-year...
chrisjj 1y ago
> Celebrating the molecule that changed the world "The"?? There are multiple.
7thpower 1y ago
Story Time: After I graduated, I went to work for a large PE firm that most of you probably hate, working for one of their subsidiaries focused on energy who happened to have a couple refineries. As someone passionate about renewables, I was actually excited to go see the underbelly of one of the most evil companies. I also wanted to learn more about the energy industry and the maze of pipes that looked like steel spaghetti to me.. it was also always in the back of my mind that those student loans wouldn't pay for themselves. I started off in IT but eventually was fortunate enough to land a job focusing on their developing new products with other portfolio companies that focused on addressing challenges in O&G. One of the things I prided myself on was spending time, boots on the ground, with the people who were doing the day to day work and learning about what there problems were. This included a lot of escorted trips through the plant learning about the chemical processes as well as work processes, etc. One of the things I had picked up on was how nasty benzene was, this was widely acknowledged at the time by the company, and not in the typical window dressing sort of way that these things are often glossed over. Well long story short, one day I'm standing on top of grating resting above a concrete pit coming off a refining unit while they are using a truck sized vacuum to extract the liquid (guess what the truck is called), which is told is an every day occurance. Standing a few feet above the liquid, it looks like dirty water. As an afterthought, I ask "what is this liquid?". "Oh, it's just benzine" ... taps 4 gas meter that's supposed to keep me safe from anything "well isn't this thing supposed to go off?" "Not all the time" Never did that again. I was surprised it was treated so nonchalantly, but when your job is to deal with dangerous stuff day in and day out, I guess certain things don't raise alarms. I, of course, didn't ask what concentration it was, etc., I just filed a few lessons away. But it's always stuck with me how routine some of this incredibly dangerous work can seem, and how difficult it must be to differentiate types of danger when they're not things that are obviously dangerous, such as having your finger chopped off, or worse, ruining a nice set of steel toes. Anyway, that's my benzine story.
jeffhwang 1y ago
Hope it’s ok to share my chemistry Instagram with a plastic model of Hexabenzocoronene (HBC) that was mentioned in the article.[1] I posted similar photos of other polycyclic aromatic hydrocarbons (PAH) including napthalene, which are also mentioned in the article. [2] In all, I had about 10 posts on PAH’s for laypeople and chemists who want to admire the structure of these fascinating saturated planar hydrocarbons. [1] https://www.instagram.com/p/CxUs8YzO28Y/?igsh=NTc4MTIwNjQ2YQ== https://www.instagram.com/p/CxUs8YzO28Y/?igsh=NTc4MTIwNjQ2YQ... [2] https://www.instagram.com/p/CxFCSueOrA2/?igsh=NTc4MTIwNjQ2YQ== https://www.instagram.com/p/CxFCSueOrA2/?igsh=NTc4MTIwNjQ2YQ...
- bravesoul2 1y ago
  More than OK to share. Thanks!
- Lalabadie 1y ago
  This is really cool, thank you for sharing it!
- deleted 1y ago
  [deleted]
- jeffhwang 1y ago
  Thanks for the interest! Here are my other aromatic posts, and beyond benzene, I have posts on these PAHs: * 1,3,5-tris(biphenyl)benzenei -- https://www.instagram.com/p/CxZgDpWLk2b/ https://www.instagram.com/p/CxZgDpWLk2b/ * hexa-cata-hexabenzocoronenei -- https://www.instagram.com/p/CxW0-PkRbK4/ https://www.instagram.com/p/CxW0-PkRbK4/ * rubrene -- https://www.instagram.com/p/CUdK6MhPw9p/ https://www.instagram.com/p/CUdK6MhPw9p/ * coronene -- https://www.instagram.com/p/CxRfv6yx0VL/ https://www.instagram.com/p/CxRfv6yx0VL/ * tetracene -- https://www.instagram.com/p/CxHuVt2uKBk/ https://www.instagram.com/p/CxHuVt2uKBk/ * dibenz[a,j]anthracene -- https://www.instagram.com/p/CxKLUXTOq2o https://www.instagram.com/p/CxKLUXTOq2o * benzene -- https://www.instagram.com/p/CxCtSEWOEuu/ https://www.instagram.com/p/CxCtSEWOEuu/ * summary of 10 molecules in pen and ink -- https://www.instagram.com/p/CxbtJZHPGGL/ https://www.instagram.com/p/CxbtJZHPGGL/
randomcarbloke 1y ago
I used to have to use this for potentiometric titrations, along with toluene for maybe 6 months I was exposed to this stuff daily...how fucked am I?
smadge 1y ago
Maybe the target audience doesn’t need to be reminded, but benzene is really toxic and dangerous and it’s odd the article doesn’t mention that.

238 points by Brajeshwar 1y ago

[flagged]

> Its peculiar behaviour, such as its surprising stability despite being highly unsaturated, hinted at a deeper mystery that would not be fully resolved until the mid-19th century with the proposal of its cyclic structure. How were chemists in the early 19th century able to determine benzene must be highly unsaturated without knowing its structure? Did they simply combust it and measure the amount of water vapor and carbon dioxide produced?

deleted 1y ago
[deleted]
perihelions 1y ago
I think you're right, https://en.wikipedia.org/wiki/Kaliapparat https://en.wikipedia.org/wiki/Kaliapparat
- sndean 1y ago
  Yeah an apparatus like that and work out that benzene had a very different carbon dioxide to water ratio than something like hexane.
- chermi 1y ago
  How cool, it's still in the ACS logo! Germans have the best names lol. Calibration apparatus.
  - namibj 1y ago
    No, it's from al kali ne.
  - perihelions 1y ago
    > "Calibration apparatus" I believe it's kali from German Kaliumhydroxid[0] (KOH, what it uses to dissolve CO2), from the same "potassium" root as al-kali in English, from medieval Arabic[1]. (And also metonymically a name for the coastal salt-marsh plant[2] from which medieval workers sourced potash/potassium[3]. I actually submitted that plant to HN [4] a few days ago, but no one was excited about it. They were once an essential ingredient in glassmaking, hence their other name, "glasswort"). [0] https://de.wikipedia.org/wiki/Kaliumhydroxid https://de.wikipedia.org/wiki/Kaliumhydroxid [1] https://en.wiktionary.org/wiki/kali#English https://en.wiktionary.org/wiki/kali#English [2] https://en.wikipedia.org/wiki/Salsola_kali https://en.wikipedia.org/wiki/Salsola_kali [3] https://en.wikipedia.org/wiki/Potash#History https://en.wikipedia.org/wiki/Potash#History [4] https://news.ycombinator.com/item?id=44128748 https://news.ycombinator.com/item?id=44128748
    - ahartmetz 1y ago
      The literal meaning is indeed potassium apparatus / device / contraption. The Kali part is indeed shortened from Kaliumhydroxid. Strangely enough, the modern German name is Fünf-Kugel-Apparat, "five balls apparatus". I found that one simply by going through "Other languages" on Wikipedia. And benzene is called Benzol in German. And gasoline is called Benzin - that word has false friend potential because it seems more similar to benzene. It is also not derived from the name of Carl Benz of Mercedes-Benz fame who used it in the first practical automobile that he invented.
isoprophlex 1y ago
What these early chemists accomplished with, to our eyes, extremely crude methods is astounding. Physical methods like weighing, burning and collecting residue; describing crystallization and precipitation behavior, even smelling (and sometimes tasting) was at one point a routine thing to do.
- deleted 1y ago
  [deleted]
- radicalbyte 1y ago
  The story of how Oxygen was discovered was super interesting and involved all of these methods.
  - bravesoul2 1y ago
    Wow. Pre that discovery what did they think explained phonomenon like snuffing out a candle. Or blowing air on a fire.
    - bruckie 1y ago
      https://en.wikipedia.org/wiki/Phlogiston_theory https://en.wikipedia.org/wiki/Phlogiston_theory
  - implements 1y ago
    Argon is an interesting one. A comparison between chemically synthesised nitrogen and ‘pure’ nitrogen extracted from the air (with the oxygen, carbon dioxide and water removed) revealed a discrepancy: https://en.wikipedia.org/wiki/Argon#History https://en.wikipedia.org/wiki/Argon#History https://www.youtube.com/watch?v=loqudG71uBM https://www.youtube.com/watch?v=loqudG71uBM (Chemistorian, noble gases)
Horffupolde 1y ago
Yes.
jcranmer 1y ago
There's a two step-process to stochiometry. The first step, as people have elaborated below, is combust the compound and measure the weights of various oxides, which (after the atomic masses of the relevant elements were settled around the 1820s) lets you work out the empirical formula of an unknown molecule. For benzene, this would tell you that there is 1 C : 1 H, but this doesn't tell you if it's C₄H₄ or C₆H₆ or C₁₁₁H₁₁₁. The second step is to determine the molar mass of your compound, which requires finding something that depends on the amount of substance but not the mass directly. (In modern times, this is primarily mass spec). Back in the 19th century, this is probably abusing the ideal gas law, which lets you compute the number of moles in a gas given the pressure, temperature, and volume of a vessel. Combine this with the mass of that container, and you know how much a mole weighs. If you get out, say, 77g/mol, and you know that the ratio is 1 C : 1 H, well, the only formula that makes sense is C₆H₆ (which should ideally have 78g/mol, but you might not get the right answer for various experimental reasons).

Brajeshwar 1y ago

I realize the article is asking for a login (a free account). Here is the Archived link https://archive.is/X1iHZ https://archive.is/X1iHZ

AStonesThrow 1y ago

[dead]

chasil 1y ago

"...benzene holds a special place in education. Generations of high school and university students have been introduced to the elegance of its structure and the profound mystery surrounding its stability." Admire it from a distance. "Benzene is classified as a carcinogen, which increases the risk of cancer and other illnesses, and is also a notorious cause of bone marrow failure. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, bone marrow abnormalities and cardiovascular disease. "...There is no safe exposure level; even tiny amounts can cause harm." https://en.wikipedia.org/wiki/Benzene#Health_effects https://en.wikipedia.org/wiki/Benzene#Health_effects

aszantu 1y ago
Lots of sunscreen and other beauty products seem to be contaminated with benzene. Johnson & Johnson was caught a few times putting it in baby powder or something
- dylan604 1y ago
  J&J's baby powder situation was related to asbestos[0]. So it must be under your "or something" hand wavy qualifier. If you're going to sling dirt, at least make it accurate. The benzene use was in other products like sunscreen[1] [0]https://www.reuters.com/investigates/special-report/johnsonandjohnson-cancer/ https://www.reuters.com/investigates/special-report/johnsona... [1]https://www.jnj.com/media-center/press-releases/johnson-johnson-consumer-inc-issues-voluntary-recall-of-specific-neutrogena-and-aveeno-aerosol-sunscreen-products-due-to-the-presence-of-benzene https://www.jnj.com/media-center/press-releases/johnson-john...
  - bee_rider 1y ago
    They mention the sunscreen in the other sentence of the post. I gotta say, your post comes off (maybe I’m misreading it) as a bit critical, given that you seem to agree with the other poster as to the underlying problem (frequent contamination issues).

_WhySoSerious_ 1y ago

Kekule who dreamt of 6 serpents each eating others tail and discovered the hexavalent structure, meanwhile cries in a corner. No mention of Kekule in the article.

carbocation 1y ago
This does seem like an important omission.
JKCalhoun 1y ago
Agree: https://en.wikipedia.org/wiki/August_Kekulé#Kekulé's_dream https://en.wikipedia.org/wiki/August_Kekulé#Kekulé's_dream (I had the impression from somewhere else that his "reverie or day-dream" might have instead been a pipe dream — as in the literal pipe dream (opium?). But I can now find nothing to substantiate this at all so, maybe just ignore.) EDIT: perhaps I was reading too much into this page from the Golden Book of Chemistry: https://www.slideshare.net/slideshow/the-golden-book-of-chemistry-experiments/3491280#81 https://www.slideshare.net/slideshow/the-golden-book-of-chem...
FlyingSnake 1y ago
Omitting such an important story from the article feels sloppy. For me, no other story from Chemistry is as fascinating as Kekule dreaming up Benzene’s molecular structure. An important reminder to me about the power of narrative and storytelling.
epiccoleman 1y ago
For a tangent on Kekule, I really enjoyed Cormac McCarthy's essay The Kekule Problem - published in 2017 and apparently his first published work of non-fiction.
- jihadjihad 1y ago
  Link to essay: https://nautil.us/the-kekul-problem-236574/ https://nautil.us/the-kekul-problem-236574/
  - 1y ago

vondur 1y ago

I've read that back in the day chemists used to nearly bathe in this stuff. Now it's rarely used in instructional chem labs. Heck as an undergrad in the 90's we were using Potassium Dichromate as an oxidizer. I spilled some on me and it ate through my lab coat and shirt beneath it. Probably should have had an apron on too...

andygeorge 1y ago

I was a kid when there was a Benzene spill up where I lived at the time (Duluth, MN). I remember having to evacuate to our aunt's house out of town. My dad stayed at home doing yardwork until he felt "a little lightheaded" and finally joined us. https://en.wikipedia.org/wiki/1992_Nemadji_River_train_derailment https://en.wikipedia.org/wiki/1992_Nemadji_River_train_derai...

ThrowawayTestr 1y ago
Benzene is really bad for you

scottlawson 1y ago

I love articles like this that give the context and history to important but not often talked about molecules. I enjoyed this as much as the "chemicals I will never work with" series.

jasonthorsness 1y ago

Seattle’s Gas Works Park has some strange equipment to address the benzene contamination. Bold move to make industrial sites into parks (it is one of the best in Seattle though!) Edit: better link https://apps.ecology.wa.gov/cleanupsearch/site/2876 https://apps.ecology.wa.gov/cleanupsearch/site/2876 Original link was older 2005 report: https://apps.ecology.wa.gov/cleanupsearch/document/1509 https://apps.ecology.wa.gov/cleanupsearch/document/1509

robocat 1y ago
Relevant sections from the 2005 report: 3.1 Benzene. On the east side of the Park, south of the Play Barn the groundwater is contaminated with benzene. An interim action removed a benzene containing LNAPL that had been discovered during site investigation. The remedy chosen for benzene was an air-sparging/soil vapor extraction (AS/SVE). The AS/SVE system covers approximately 1.5 acres of the Park. It is unnoticeable to Park users except for a small equipment box near the Towers. . An action level was calculated based on MTCA Method B surface water criteria and a dilution attenuation factor (DAF). The calculation used to set the DAF and the action level for benzene is given in appendix 1. 4.1 Benzene. Benzene concentration in the compliance well OBS-1 remains below the action level but above the method B groundwater cleanup level. The remedy, therefore, remains effective. See figure 3 below.

divbzero 1y ago

It amazes me that the same person who discovered benzene also discovered electromagnetic induction and Faraday’s laws of electrolysis.

ipdashc 1y ago
> and Faraday’s laws of electrolysis Wow, what are the chances he discovers something with a name like that?
nanna 1y ago
And wasn't Faraday also a self-taught amateur whose maths was so poor that he couldn't even do trigonometry? A beacon of hope for those of us without doctorates in physics out here...
- Qem 1y ago
  He was lucky being born when there was still a lot of low hanging fruit lying around.

groos 1y ago

I once pulled on a glass pipette too hard and got benzene in my mouth. This was 36 years ago, still doing well :-)

joloooo 1y ago

Interesting article. I have always viewed Benzene as a bogeyman of sorts. My parents both interacted with it often throughout my life. My dad was a chemical engineer for an oil company, and he often spoke of spills and incidents. As a kid, I never understood what it was, but the tone and urgency were always something scary. I also strongly suspect my mother's Benzene exposures (nurse cleaning lab slides with Benzene and no PPE) led to me battling Langerhans Histiocytosis throughout my childhood. https://en.wikipedia.org/wiki/Langerhans_cell_histiocytosis https://en.wikipedia.org/wiki/Langerhans_cell_histiocytosis

jordanb 1y ago
"Benzene is what anti-nuclear people think nuclear waste is."

quietbritishjim 1y ago

I'll admit I know very little chemistry, but I think the article would've been much better for people like me of it included any specific examples at all of benzene uses. It's filled with assurances that it's important and used all over the place but I didn't find that very enlightening.

philipkglass 1y ago
https://en.wikipedia.org/wiki/Benzene#Uses https://en.wikipedia.org/wiki/Benzene#Uses Benzene is used mainly as an intermediate to make other chemicals, above all ethylbenzene (and other alkylbenzenes), cumene, cyclohexane, and nitrobenzene. More than half of the entire benzene production is processed into ethylbenzene, a precursor to styrene, which is used to make polymers and plastics like polystyrene. Some 20% of the benzene production is used to manufacture cumene, which is needed to produce phenol and acetone for resins and adhesives. Cyclohexane consumes around 10% of the world's benzene production; it is primarily used in the manufacture of nylon fibers, which are processed into textiles and engineering plastics. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives, and pesticides. It's an important feedstock in the chemical industry but it is no longer used directly in household products. It used to be common in solvent/glue/grease remover formulations before the health hazard was widely appreciated.
andrewflnr 1y ago
It's kind of hard to explain how widespread a usage like "solvent" is. A huge amount of chemical reactions are most convenient to do in a liquid, a liquid that can dissolve the materials you're working with. That's a solvent. Benzene can dissolve a lot of things, including some that are really hard to dissolve otherwise. So it can be used for a huge variety of reactions, but as the sort background player that you might not pay attention to unless you can't have it. It's a little like asking "what are the uses of water in chemistry", where you're tempted to answer, "um, everything?" Not quite, but not that far off either. (And with more cancer of course.) Edit: disclaimer, I'm not a chemist, just an interested layman.
- deleted 1y ago

trebligdivad 1y ago

The article talks about the wonders of bucky balls and nanotubes - does anyone know what useful stuff has come out of those yet? I think I heard there's some work on nanotubes coming up on transistors in the next gen of chips? Not sure what bucky balls and other fullerenes are being used for? (I remember originally there was talk of lubricants?)

bell-cot 1y ago
> does anyone know what useful stuff has come out of those yet? Quip: Every chemical researcher's #1 need is for research funding, no?
lightedman 1y ago
For useful carbon nanotubes, look no further than nanotape. That shit is extremely strong and will happily peel the paint or wallpaper from your walls.

euroderf 1y ago

Benzene must've been examined down to the nth degree in quantum analysis. Maybe there's an article ?

toddm 1y ago
Lots of them. I wrote 6 on my way to my Ph.D. in the late 1990s, and there was plenty of prior art at that time. Here's one of mine, see references therein as well: https://pubs.aip.org/aip/jcp/article-abstract/110/7/3326/475549/Quantum-dynamics-of-overtone-relaxation-in-30-mode https://pubs.aip.org/aip/jcp/article-abstract/110/7/3326/475...

jabl 1y ago

I remember in high school chemistry (or physics?) we had a wooden model of the benzene ring with the ground state molecular orbitals. Diameter about 30cm.

k__ 1y ago

I did an internship at a chemical laboratory once. The older folks told me that they aren't allowed to use the awesome stuff anymore. Back in the days, they would use Benzene for everything, the only stuff that would get the lab floors clean at the end of the day. Same with asbestos, leaded fuel, and whatnot. Compounds that are perfect for their use cases, yet highly toxic.

pumnikol 1y ago
One of my elderly colleagues once told me that at the end of each day, they'd put all the lab coats in a big vat of benzene to clean them. The next day, they took them out, let them dry for a short while and then just put them on again. I think it was in the early 80s? He did develop cancer later.
fuzzfactor 1y ago
This was the traditional solvent for cleaning up and removing excess ink in print shops all over the place. Often still known by its archaic name Benzol when I was growing up. In high school, walking by the student print shop you could smell it way down the hall at all times. The chem labs were not nearly as bad because they had better ventilation to begin with. Plus before my time benzene had also been prized as high-octane motor fuel for early cars back when it was obtained for sale naturally by removal from aromatic crude oils in some refineries. This was not such pure benzene however the significant percentage of impurities at the dispenser acted with an "antifreeze" effect and it handled no differently than regular gasoline below 32 degrees F. Pure benzene freezes at about 40 degrees F, and that pure of a hydrocarbon ended up being too expensive to burn anyway. IIRC it can really make a lawn mower cut taller grass than premium gasoline, and scientifically it does have about 100 antiknock rating so it's no surprise.
- k__ 1y ago
  "Often still known by its archaic name Benzol" In German, that's the regular name, haha.
  - chasil 1y ago

timthorn 1y ago

The Royal Institution, where Faraday first isolated Benzene, is celebrating with a Discourse next month: https://www.rigb.org/whats-on/discourse-celebrating-200-years-benzene-whale-oil-aromaticity https://www.rigb.org/whats-on/discourse-celebrating-200-year...

chrisjj 1y ago

> Celebrating the molecule that changed the world "The"?? There are multiple.

7thpower 1y ago

Story Time: After I graduated, I went to work for a large PE firm that most of you probably hate, working for one of their subsidiaries focused on energy who happened to have a couple refineries. As someone passionate about renewables, I was actually excited to go see the underbelly of one of the most evil companies. I also wanted to learn more about the energy industry and the maze of pipes that looked like steel spaghetti to me.. it was also always in the back of my mind that those student loans wouldn't pay for themselves. I started off in IT but eventually was fortunate enough to land a job focusing on their developing new products with other portfolio companies that focused on addressing challenges in O&G. One of the things I prided myself on was spending time, boots on the ground, with the people who were doing the day to day work and learning about what there problems were. This included a lot of escorted trips through the plant learning about the chemical processes as well as work processes, etc. One of the things I had picked up on was how nasty benzene was, this was widely acknowledged at the time by the company, and not in the typical window dressing sort of way that these things are often glossed over. Well long story short, one day I'm standing on top of grating resting above a concrete pit coming off a refining unit while they are using a truck sized vacuum to extract the liquid (guess what the truck is called), which is told is an every day occurance. Standing a few feet above the liquid, it looks like dirty water. As an afterthought, I ask "what is this liquid?". "Oh, it's just benzine" ... taps 4 gas meter that's supposed to keep me safe from anything "well isn't this thing supposed to go off?" "Not all the time" Never did that again. I was surprised it was treated so nonchalantly, but when your job is to deal with dangerous stuff day in and day out, I guess certain things don't raise alarms. I, of course, didn't ask what concentration it was, etc., I just filed a few lessons away. But it's always stuck with me how routine some of this incredibly dangerous work can seem, and how difficult it must be to differentiate types of danger when they're not things that are obviously dangerous, such as having your finger chopped off, or worse, ruining a nice set of steel toes. Anyway, that's my benzine story.

jeffhwang 1y ago

Hope it’s ok to share my chemistry Instagram with a plastic model of Hexabenzocoronene (HBC) that was mentioned in the article.[1] I posted similar photos of other polycyclic aromatic hydrocarbons (PAH) including napthalene, which are also mentioned in the article. [2] In all, I had about 10 posts on PAH’s for laypeople and chemists who want to admire the structure of these fascinating saturated planar hydrocarbons. [1] https://www.instagram.com/p/CxUs8YzO28Y/?igsh=NTc4MTIwNjQ2YQ== https://www.instagram.com/p/CxUs8YzO28Y/?igsh=NTc4MTIwNjQ2YQ... [2] https://www.instagram.com/p/CxFCSueOrA2/?igsh=NTc4MTIwNjQ2YQ== https://www.instagram.com/p/CxFCSueOrA2/?igsh=NTc4MTIwNjQ2YQ...

bravesoul2 1y ago
More than OK to share. Thanks!
Lalabadie 1y ago
This is really cool, thank you for sharing it!
deleted 1y ago
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jeffhwang 1y ago
Thanks for the interest! Here are my other aromatic posts, and beyond benzene, I have posts on these PAHs: * 1,3,5-tris(biphenyl)benzenei -- https://www.instagram.com/p/CxZgDpWLk2b/ https://www.instagram.com/p/CxZgDpWLk2b/ * hexa-cata-hexabenzocoronenei -- https://www.instagram.com/p/CxW0-PkRbK4/ https://www.instagram.com/p/CxW0-PkRbK4/ * rubrene -- https://www.instagram.com/p/CUdK6MhPw9p/ https://www.instagram.com/p/CUdK6MhPw9p/ * coronene -- https://www.instagram.com/p/CxRfv6yx0VL/ https://www.instagram.com/p/CxRfv6yx0VL/ * tetracene -- https://www.instagram.com/p/CxHuVt2uKBk/ https://www.instagram.com/p/CxHuVt2uKBk/ * dibenz[a,j]anthracene -- https://www.instagram.com/p/CxKLUXTOq2o https://www.instagram.com/p/CxKLUXTOq2o * benzene -- https://www.instagram.com/p/CxCtSEWOEuu/ https://www.instagram.com/p/CxCtSEWOEuu/ * summary of 10 molecules in pen and ink -- https://www.instagram.com/p/CxbtJZHPGGL/ https://www.instagram.com/p/CxbtJZHPGGL/

randomcarbloke 1y ago

I used to have to use this for potentiometric titrations, along with toluene for maybe 6 months I was exposed to this stuff daily...how fucked am I?

smadge 1y ago

Maybe the target audience doesn’t need to be reminded, but benzene is really toxic and dangerous and it’s odd the article doesn’t mention that.