In both this benzene video and the lead video, you brought up engine knock (or ping) but avoided telling us anything about the chemistry of that process, and how it is altered by either benzene or tetra ethyl lead. Just saying the car has trouble going up hill is not much of a chemistry lesson.
I am disappointed that you didn't take this opportunity to inform us more specifically.
@cath1594 Alcohol and water form an azeotrope (a mixture with a lower boiling point that either pure substance).
Pure ethanol boils at 78.3 C, and pure water boils at 100C. The catch is that a mixture of 96% ethanol/4% water boils at 78.1 C.
When you distil a mixture of ethanol and water (as long as you start from more than 4% water) - the first thing that distills is the 96/4% mixture, and this continues until all the ethanol has distilled. Then only the water is left.
In my highschool chemistry class we just learned that benzene does not in fact contain any double bonds, but that each bond is an intermediate between double and single. Now I don't know what to believe.
I visited the Kekulé memorial in Bonn this year when I went to my partner's school reunion there and visited the laboratory of Justus von Liebig in Giessen - when the professor goes to Darmstadt next time - perhaps he should take a trip to Liebig's laboratory as he was one of the first to develop lab based teaching.
We did the same nitration of benzene at college a few months back!! Although the teacher was more worried about letting the reaction develop too quickly (Apparently 3 nitrile groups on a benzene is quite explosive!).
Just finished A level chemistry today (I'm off to study physics in the autumn at uni). I'm missing it already :'(
OH ahh this is interesting, in the Scotish education of Higher Chemistry, we're taught that benzene rings have a different type of bond, we were told that they had 6H and 6C, and we were asked how it could be built, I suggest a ring shape with 3double bonds and 3 single, I was told that this was wrong, and that there was something called "benzene bonds" that was something between the two (we were told the difference in the length of bonds as "proof") could you confirm which is correct please? :D
@MICHAELJONSTON Essentially, that is correct, however they're not usually referred to as "benzene bonds", because they're in no way exclusive to Benzene. It's hard to describe in text form, but what we see in benzene is an example of "delocalised bonding". Imagine your idea, a ring of 6 carbons, joined by alternating single and double bonds. Then "move" the double bonds across by one carbon, and you have another isomer. Benzene rapidly interconverts between these isomers.
@MICHAELJONSTON The 3 extra bonds move around the ring so fast, that it has the overall effect of all 6 bonds being part way between a single and a double bond.
Like mentioned, this isn't only true for benzene. Many important organic molecules contain a system like this, whereby the 2nd bond of a double bond can become "delocalised" and move about the molecule, and can often be the driving force behind some of the most importan organic reactions!
My chemistry teacher said she once caught one of her students drinking the lab's ethanol from the bottle. Now, I know of another reason why he was stupid. -_-
After about a whole year, i came back to this video. I started my A-levels this year and I am just studying reactions of aromatic compound . It feels so great to know more about this compound and came back to this video!
Is there theoretical evidence for all the lengths of the C-C bonds being equal, without measuring them by X-Rays or scanning tunneling microscopes? Or is the distinctive structure with its delocalisation of electrons only proved by those techniques?
Brauch keinen Freund Kein Kokain Brauch weder Arzt noch Medizin Brauch keine Frau nur Vaselin Etwas Nitroglyzerin Ich brauche Geld für Gasolin Explosiv wie Kerosin Mit viel Oktan und frei von Blei Einen Kraftstoff wie Benzin Gib mir Benzin :)
In Sweden we call petrol, or gasoline, "bensin" which is pronounced pretty much the same as benzene. A fair guess would be that the name comes form the benzene present in the petrol, though led based petrol ALSO was called "bensin".
Was benzene present in led based petrol as well? If not, why do you think the swedish word for led based petrol was "bensin"?
@pierreaupeix That's a good question. People in Sweden really are smart. If I moved to Sweden from America would they accept me? I am starting to dislike this place more and more.
@Mooogzilla It depends what lab ethanol you're on about. Stuff you get to use relatively freely in the lab is IMS alcohol (industrial methylated spirit), which is mixed with Methanol. Methanol makes you go blind. Lovely stuff.
Actual pure ethanol like the Prof. describes is heavily regulated for lab use, as it's deemed pure and drinkable enough to qualify for taxation in the UK. At my university, undergraduates must sign it out, and aren't often allowed to dispense it themselves.
@periodicvideos May you please do a video on the basics of determining shapes of molecules? I'm curious as to how we know shapes like trigonal pyramidal, tetrahedral, octahedral, etc... (i'm from the states, so I apologize if those terms are unfamiliar to you....)
@TheRobster94 Have a look at a concept called Valence Shell Electron Pair Repulsion Theory (VSEPR Theory). It forms the basis of how chemists theoretically determine the shape of molecules, by predicting the interactions between electron pairs in the molecule.
Of course, VSEPR (and similar theories) are theoretical models. To accurately determine and confirm these hypothetical structures, you can use techniques such as crystallography to "see" the shapes of molecules
He says that benzene is very restricted and controlled, but in my AP Chem class we used it in several labs during our organic chemistry unit. Not sure if this is typical or not. Keep up the good work!
I drank a good mouthfull of Avation fuel (100LL Avgas) the a couple of years ago so im probley full of benzene now! lol... It wasn't pleasant I was burping petrol for hours, Good job i didn't smoke!
I don't think they have any reason to put it in grain alcohol (Everclear) or vodka or any other alcoholic beverage, since none of these need to be anhydrous.
I'm interesting in knowing how Faraday made his benzene and what process may have created the trace impurities. Is there any explanation for this? Thanks.
@mistermuffin420 When I did chemistry in high school... the maths content was at a minimum so I like it better than physics. Physics, especially Newtonian physics bored me to death so I would always like chemistry.
These days it's all maths. Titration equations, entropy, enthalpy, equilibria law. Grr, my chemistry exams are mostly maths. I have to do natural logs in chemistry...
@vulgarmachine2 these days.... I have my grandmothers Organic chem notes from the late 40's, its all pretty much the same. She didn't have a graphing calculator though.
I guess if they are algebraic equations it can be tolerated (in my point of view) but once its gets to calculus then I go "eek!". I always like organic chemistry anyway... You just have to learn simple (but long) reaction schemes :)
Tell me about it. MInd you, so long as you can understand where the dipole moments form you can understand most of the reaction mechanisms. Plus there's that lovely graph that links the reactions of all the hydrocarbons which I think is lovely! haha!
Did IB Chemistry at Higher Level for the past 2 years... Took my final exams a couple of months ago and I totally agree >.< A lot of maths. I've always had trouble with acid base equilibria problems :\
I had always wondered exactly why reagent grade ethanol is labeled unfit for consumption (besides the fact that drunk chemists and laboratories don't mix, of course).
Back in the day.. 1986, my inorganic chem teacher, old as dirt, lectured us, "when I was a chemist we were up to our elbows in Benzine all day long. Never hurt me, I'm as healthy as the day I was born...."
Benzene is volatile at room temperature. So in Lead free Petrol the Benzene is added to reduce knock. If you do low mileage in your car, (ie you tank of petrol is over a month old) does the Benzene content reduce and you will suffer knock on this tank of petrol?
@hugiesrox All fuel tanks are allowed to vent/breathe. I suspect benzene is the major factor sited against using old unleaded fuel, say on my unleaded petrol grass mower. It says so in the petrol mowers instructions! Old, is over a month, old for my petrol mowers manufacturer. I can buy an additive than extends my unleaded petrol life for a year!
@ClercLe Try accelerating up a steep hill in high gear, and listen for a tinkling sound. Knocking, pre-ignition is sometimes called 'pinking' and this is perhaps a better description. Essentially it's an explosion in the cylinder rather than a burn. Diesels would always pink if they used a carburator, because all the mixture would ignite at the same time, but they don't, they're fuel injected, and burn progressively as the fuel is injected.
Wait around 1:50 you say the benzene has a single bond then a double bond (alternating around the molecule). i thought that all of the bonds were the same length so they cannot alternate and that there are delocalised electron fields above and below the molecule.
@bullets0000 Here methylbenzene, or toluene, is also used in place of benzene. I believe xylene (dimethylbenzene) is an even better alternative, regarding safety and such.
I have a question, according to a link from Youtube, there is a concern about soft drinks having benzene due to the reaction of x Bensoate (Na or K), and Citric Acid, which when both chemicals are in a soda (and they are!), and are exposed to heat or time, they convert to Benzene. The link sent you to a news article stating 2-4x the benzene levels considered safe for water are found in sodas. Is this reaction correct? What would cause it (ie how much time or heat?), etc?
@zbret The reaction is correct, although it could be an instable reaction, soft drinks have Sodium or Potassium benzoate in it, wich produces benzene and you ingest it, the reaction is not always certain, as you said it need unknow time and heat but it exists, but we should concern ourselfs more of what comes from Air pollution or products we use in the daily basis such as detergents,perfumes etc.
@tsumui well ya. but .. what about plasma? Can all elements exist in a state of plasma? I know my basic chem and physics,, was just wondering about the "extra states of matter" I.E. plasma and super fluids...
@RitchieFelix for plasma this might work (but it will be verey dificult for some elements) but superfuildity is something rather complicated and I am not sure if there are too much chemicals that can be made superfuid... the only one I know of is Helium...
I should add a couple notes. The stutter/lurch the Professor described would more likely be caused by a miss - fuel NOT burning when it SHOULD. If this happens, you need to check your car's ignition timing or the spark plug gap.
As well, modern cars with electronic ignition can run on low-grade fuel without knocking, but this will still cause damage over time, and the performance will be poorer. Modern cars with Direct Injection can also cope by firing the fuel at the right time, like a Diesel.
Well, what happens to a car is that you get a noise under the hood called a 'knock," from the fuel pre-igniting before the piston gets to the top of the cylinder. Benzine decreases the ease of which which the fuel burns, meaning it only goes off when it's supposed to. High-performance cars have a very high Compression ratio, which, (as in a Diesel,) causes the fuel to ignite purely by the squeezing of the fuel/air mixture. If you have a knock, check your timing or put premium petrol in it.
I love these videos. When I was a prospective bachelors student I visited the University of Nottingham's chemistry department. But alas, at the time I despised Chemistry and decided that Chemistry all together was not the way to go.
These videos kind of make me wish I went. They have certainly re-ignited my interest. Also, I think I have a bit of a crush on Debbie and Professor Poliakoff has a great personality, they help.
Why was the label on the bottle covered up with black marker? There is only one structural form of pure benzene, and it was already drawn for us, so it's not like they censored the structure.
When I took organic chemistry as an undergraduate in 1970 we used benzene by the GALLON for everything! It's an excellent solvent. We practically drank the stuff. And when we were finished with it, we simply dumped it down the drain.
Benzine has one of the prettiest Lewis structures imo. Ever notice the more symmetrically pleasing they are the more dangerously toxic they seem to be?
@techguy33 Because it has a high freezing point, you can have benzene in another solvent, and precipitate it out after hot filtration. As it cools, crystals form, and then you can just get rid of the solvent and voila! nice pure benzene
That was a great video, I enjoyed it very much - I've learned a bit about aromatic compounds in organic chemistry at college and benzene somehow always managed to get my attention in a special way. Maybe because my teacher told us to think of its electronic cloud as a donut because of the electron delocalization. I also didn't know why these coumpounds were called "aromatic", but now I do. :D I'm looking forward to see more videos! Greetings from a bioengineering student from Portugal :)
The term aromatic is also to do with the enhanced stability of the benzene ring and the fact it undergoes electrophilic substitution reactions rather than the addition reactions of the usual conjugated trienes.
Nitration of Benzene; now there's a reaction you'd not allowed to do in schools nowdays. I recall my Dad nitrated benzene during his A levels 30 or so years ago.
When my brother was about 6 or 7, he thought he would be a smart and take a swig of dad's beer that he had setting while he was working on his truck.
Unfortunately, the can had gas in it, not beer (I guess he was working on the carb?)
That was a pleasant experience. Almost as pleasant as the huge dose of chlorine gas i hit him with (accidentally) while playing with an old school freon leak detector, or watching him pass out after hitting two balloons worth of helium off my uncle's tig welder.
I'm kinda disappointed the video didn't talk about how useful benzene is to synthesize new organic compounds :( although he did mention making nitro-benzene. He should of kept going and explaining different things that can be produced from it.
this might be a really basic chemistry question so excuse my lack of knowledge on the subject.. how did the chemists of the past they are speaking on know it had 6 carbons and 6 hydrogen atoms?
@lejink First they would have burned some benzene in excess oxygen and measured the ratio of CO2 to water vapor given off. That told them Benzene was made of equal parts H and C. After that, they could determine the number of molecules there are in a gram of C6H6 by applying the ideal gas law to some benzene vapor. Then they figure out how many CH groups it takes to equal that molecular mass.
@lejink one simple way is to burn it - benzene will burn with a yellow, sooty flame due to higher carbon to hydrogen ratio (incomplete combustion), whereas alkanes (non-aromatic compounds) burn with a clearer flame (more complete combustion to water and CO2).
this is good for my work on this great vid
funnyhehehhahaha 1 day ago
@ChumpusRex and @98JMA thank you both!!!!
cath1594 3 days ago
In both this benzene video and the lead video, you brought up engine knock (or ping) but avoided telling us anything about the chemistry of that process, and how it is altered by either benzene or tetra ethyl lead. Just saying the car has trouble going up hill is not much of a chemistry lesson.
I am disappointed that you didn't take this opportunity to inform us more specifically.
jpopelish 4 days ago
I was wondering, why is it that you can't get all of the water out of the alcohol by distilling it?
cath1594 1 week ago
@cath1594 Alcohol and water form an azeotrope (a mixture with a lower boiling point that either pure substance).
Pure ethanol boils at 78.3 C, and pure water boils at 100C. The catch is that a mixture of 96% ethanol/4% water boils at 78.1 C.
When you distil a mixture of ethanol and water (as long as you start from more than 4% water) - the first thing that distills is the 96/4% mixture, and this continues until all the ethanol has distilled. Then only the water is left.
ChumpusRex 1 week ago in playlist Molecular Videos (supported by Aldrich Chemistry)
@cath1594
You can get rid of the excess water after distillation by drying with an anhydrous salt such as CaCl2 or MgSO4.
98JMA 5 days ago
I wish I had that good of handwriting ): 4:20
AznAlacran 1 week ago
Everyone loves ⌬
risbolla 2 weeks ago
0:40 How do you recognize a woman's lab? Colors, colors, colors everywhere :-P
ChemistDrummer 3 weeks ago
In my highschool chemistry class we just learned that benzene does not in fact contain any double bonds, but that each bond is an intermediate between double and single. Now I don't know what to believe.
MrCasualTea 4 weeks ago
@MrCasualTea
Benzene has two isomers that are constantly changing to each other.
98JMA 3 weeks ago
dubbapon, singapon, dubbapon, singapon, dubbapon, singapon!
infintiyward 1 month ago in playlist Molecular Videos (supported by Aldrich Chemistry)
Comment removed
krapptacular 1 month ago in playlist More videos from periodicvideos
Kāpēc benzīns? Tas ir benzols. :)
Partisanification 1 month ago
Change the H to Fe and what do you have?
A ferrous wheel. :P Science teacher lol
NoRefundsXD 1 month ago
this channels caused me to LOVE science classes
uxa1 2 months ago 2
She has a very dirty lab coat.
GlowingPotion 2 months ago
You guys should do a video on toluene.
jarheadwithm16 3 months ago
I visited the Kekulé memorial in Bonn this year when I went to my partner's school reunion there and visited the laboratory of Justus von Liebig in Giessen - when the professor goes to Darmstadt next time - perhaps he should take a trip to Liebig's laboratory as he was one of the first to develop lab based teaching.
johncrwarner 4 months ago
7:00 Professors tips for health and safety when coping with the modern economy.
TheMuffinManzorz 4 months ago in playlist The Molecular Videos (supported by EPSRC)
Why does he have a massive wall of bottles? Or is that a stupid question? o.o
shoottherunner8008 8 months ago
@shoottherunner8008 He collects bottles from around the world.
Aviatorsmith 5 months ago
We did the same nitration of benzene at college a few months back!! Although the teacher was more worried about letting the reaction develop too quickly (Apparently 3 nitrile groups on a benzene is quite explosive!).
Just finished A level chemistry today (I'm off to study physics in the autumn at uni). I'm missing it already :'(
TheZefMan 8 months ago
How exactly is the shape of a molecule proved? What is used to see it?
TheNosnawS 9 months ago
OH ahh this is interesting, in the Scotish education of Higher Chemistry, we're taught that benzene rings have a different type of bond, we were told that they had 6H and 6C, and we were asked how it could be built, I suggest a ring shape with 3double bonds and 3 single, I was told that this was wrong, and that there was something called "benzene bonds" that was something between the two (we were told the difference in the length of bonds as "proof") could you confirm which is correct please? :D
MICHAELJONSTON 9 months ago
@MICHAELJONSTON Essentially, that is correct, however they're not usually referred to as "benzene bonds", because they're in no way exclusive to Benzene. It's hard to describe in text form, but what we see in benzene is an example of "delocalised bonding". Imagine your idea, a ring of 6 carbons, joined by alternating single and double bonds. Then "move" the double bonds across by one carbon, and you have another isomer. Benzene rapidly interconverts between these isomers.
Popidge 9 months ago
@MICHAELJONSTON The 3 extra bonds move around the ring so fast, that it has the overall effect of all 6 bonds being part way between a single and a double bond.
Like mentioned, this isn't only true for benzene. Many important organic molecules contain a system like this, whereby the 2nd bond of a double bond can become "delocalised" and move about the molecule, and can often be the driving force behind some of the most importan organic reactions!
Popidge 9 months ago
@Popidge
Both facinating and interesing to me :D thank you very much :D
MICHAELJONSTON 9 months ago
yo dawg, i heard you liek glasses...
twizy123 11 months ago
very good information on the benzene presence in lab alcohols. I'll keep that in mind for the future. Thanks you for everything periodicvideos
Cloud9er 11 months ago
My chemistry teacher said she once caught one of her students drinking the lab's ethanol from the bottle. Now, I know of another reason why he was stupid. -_-
japanesepoptart 11 months ago
Benzene = white gas ?
leanrio 11 months ago
After about a whole year, i came back to this video. I started my A-levels this year and I am just studying reactions of aromatic compound . It feels so great to know more about this compound and came back to this video!
yiyifone 1 year ago
I thought they used MTBE in gasoline insead of benzene??
lievenaw 1 year ago
@lievenaw The B in MTBE is Benzine
luigi90900 1 year ago
@luigi90900 haha right where did u learn that???
what do you think about methyl tertiary butyl ether = MTBE ....... retard
lievenaw 1 year ago
@luigi90900
Actually it's not. It's Methyl Tert-butyl ether... Don't worry about it man!
vulgarmachine2 11 months ago
Is there theoretical evidence for all the lengths of the C-C bonds being equal, without measuring them by X-Rays or scanning tunneling microscopes? Or is the distinctive structure with its delocalisation of electrons only proved by those techniques?
badbadalex237 1 year ago
basherofnoggins 1 year ago
In Sweden we call petrol, or gasoline, "bensin" which is pronounced pretty much the same as benzene. A fair guess would be that the name comes form the benzene present in the petrol, though led based petrol ALSO was called "bensin".
Was benzene present in led based petrol as well? If not, why do you think the swedish word for led based petrol was "bensin"?
pierreaupeix 1 year ago
@pierreaupeix That's a good question. People in Sweden really are smart. If I moved to Sweden from America would they accept me? I am starting to dislike this place more and more.
UnchainTheNight1 1 year ago
good thing I watched this video. I was considering drinking the lab ethanol.
Mooogzilla 1 year ago
@Mooogzilla It depends what lab ethanol you're on about. Stuff you get to use relatively freely in the lab is IMS alcohol (industrial methylated spirit), which is mixed with Methanol. Methanol makes you go blind. Lovely stuff.
Actual pure ethanol like the Prof. describes is heavily regulated for lab use, as it's deemed pure and drinkable enough to qualify for taxation in the UK. At my university, undergraduates must sign it out, and aren't often allowed to dispense it themselves.
Popidge 1 year ago
why does it say 0ml nitric acid?
domvasta 1 year ago
@periodicvideos May you please do a video on the basics of determining shapes of molecules? I'm curious as to how we know shapes like trigonal pyramidal, tetrahedral, octahedral, etc... (i'm from the states, so I apologize if those terms are unfamiliar to you....)
TheRobster94 1 year ago
@TheRobster94 It has to do with the state of the electrones in the atoms. It's long to explain, but yet it is nothing different.
shelteringshade 1 year ago
@TheRobster94 Have a look at a concept called Valence Shell Electron Pair Repulsion Theory (VSEPR Theory). It forms the basis of how chemists theoretically determine the shape of molecules, by predicting the interactions between electron pairs in the molecule.
Of course, VSEPR (and similar theories) are theoretical models. To accurately determine and confirm these hypothetical structures, you can use techniques such as crystallography to "see" the shapes of molecules
Popidge 1 year ago
@Popidge brilliant, thank you! :D
TheRobster94 1 year ago
He says that benzene is very restricted and controlled, but in my AP Chem class we used it in several labs during our organic chemistry unit. Not sure if this is typical or not. Keep up the good work!
me835 1 year ago
you guys should do a video on HF, the only compound every chemistry student here in Germany is really scared of
Babaji367 1 year ago
Why dont you sign a contract with some TV company offering your video expertise. and why dont you show us more experiments on each element
nithinnm123 1 year ago
anyone else keep playing 1:40 over and over again?
theNewCodingFrontier 1 year ago 9
@theNewCodingFrontier ty lol
MrBrew4321 1 month ago in playlist Molecular Videos (supported by Aldrich Chemistry)
@glenwoofit actualy aviation fuel is still leaded so no knead to worry about benzene (don't know weather or not that helps things)
regretissin 1 year ago
I drank a good mouthfull of Avation fuel (100LL Avgas) the a couple of years ago so im probley full of benzene now! lol... It wasn't pleasant I was burping petrol for hours, Good job i didn't smoke!
glenwoofit 1 year ago
LOL 6 eyes.
agun17 1 year ago
you said that there is a trace of benzene in some alcohol.can benzene be fatal if ingested in large amounts?
mobud423 1 year ago
@mobud423 That came as a shock to me too.
I don't think they have any reason to put it in grain alcohol (Everclear) or vodka or any other alcoholic beverage, since none of these need to be anhydrous.
opiumgland 1 year ago
very interesting. So are the bottles are drinking water is "N" helping cause cancer as well? Who knows... Genocide
Maat2akh 1 year ago
My chemistry teacher told me of this horrible irony
If you replace two of the hydrogens at opposite ends with Oxygens it can't exist.
For it become a "parad-ox"
Worse if they are right next to other. Then you can't do any experiments because they are "orthod-ox," and thus refuse to change XD
(It's a pun...Get it?)
Vennificus 1 year ago 21
@Vennificus
Then would replacing the 1st and 3rd hydrogen with an oxygen create a metadox?
SSJkiller 1 week ago
YAY! Now I know what TNT stands for! :D Thank you guys! I love you all!
WolfDOuka 1 year ago
I'm interesting in knowing how Faraday made his benzene and what process may have created the trace impurities. Is there any explanation for this? Thanks.
pastrychef1985 1 year ago
Dear Sir, what should I be taking into my mouth?
UncleKennybobs 1 year ago
@UncleKennybobs food?
bubzuru 1 year ago
Wait, did he just say benzene goes solid @ 6 degrees C?
:S
isop9021 1 year ago
why wouldnt the ice be 0 degrees or lower? its not like there would be additives in your ice, right?
Ele3tricEye 1 year ago
I can't believe that the lady in the video was working with benzene with the hood that open.
Ch3mG33k 1 year ago
chemistry vs. physics: which is more difficult???
mistermuffin420 1 year ago
@mistermuffin420
Physics: specially electricity, i can never undertand that.....
jjkul1 1 year ago
@mistermuffin420 When I did chemistry in high school... the maths content was at a minimum so I like it better than physics. Physics, especially Newtonian physics bored me to death so I would always like chemistry.
silentelysium 1 year ago
@silentelysium
These days it's all maths. Titration equations, entropy, enthalpy, equilibria law. Grr, my chemistry exams are mostly maths. I have to do natural logs in chemistry...
vulgarmachine2 1 year ago
@vulgarmachine2 these days.... I have my grandmothers Organic chem notes from the late 40's, its all pretty much the same. She didn't have a graphing calculator though.
freakofthewest 1 year ago
@vulgarmachine2
I guess if they are algebraic equations it can be tolerated (in my point of view) but once its gets to calculus then I go "eek!". I always like organic chemistry anyway... You just have to learn simple (but long) reaction schemes :)
silentelysium 1 year ago
@silentelysium
Tell me about it. MInd you, so long as you can understand where the dipole moments form you can understand most of the reaction mechanisms. Plus there's that lovely graph that links the reactions of all the hydrocarbons which I think is lovely! haha!
vulgarmachine2 1 year ago
@vulgarmachine2
Did IB Chemistry at Higher Level for the past 2 years... Took my final exams a couple of months ago and I totally agree >.< A lot of maths. I've always had trouble with acid base equilibria problems :\
BricksWillBeShat 1 year ago
@mistermuffin420 physics, is more difficult.
vickyboy96 1 year ago
Everybody forgets to mention the oxygen in the center of the ring... (joke)
tomtomj1990 1 year ago
the zinc metal powder bottle is in it same place as in hydrochloric acid video!
kuro96inlaila 1 year ago
A hexagon with a ring inside it... that's nuts.
BarneySaysHi 1 year ago 2
I had always wondered exactly why reagent grade ethanol is labeled unfit for consumption (besides the fact that drunk chemists and laboratories don't mix, of course).
Thumbs up!
CTyler7 1 year ago
Back in the day.. 1986, my inorganic chem teacher, old as dirt, lectured us, "when I was a chemist we were up to our elbows in Benzine all day long. Never hurt me, I'm as healthy as the day I was born...."
So.....
DrBones666 1 year ago
Those blue nitrile gloves provide almost no protections towards aromatic solvents eg. Benzene or toluene.
mewrox99 1 year ago
My name is Bond, Double Bond.
paronfisk 1 year ago 110
@paronfisk My name is bond, asymetrical bond!
ClercLe 1 year ago
@ClercLe or do I mean, My name is Bond alternate double bond!
ClercLe 1 year ago
Benzene is volatile at room temperature. So in Lead free Petrol the Benzene is added to reduce knock. If you do low mileage in your car, (ie you tank of petrol is over a month old) does the Benzene content reduce and you will suffer knock on this tank of petrol?
ClercLe 1 year ago 2
@ClercLe It shouldn't be a problem unless you are leaving you are allowing the petrol tank to vent...
hugiesrox 1 year ago
@hugiesrox All fuel tanks are allowed to vent/breathe. I suspect benzene is the major factor sited against using old unleaded fuel, say on my unleaded petrol grass mower. It says so in the petrol mowers instructions! Old, is over a month, old for my petrol mowers manufacturer. I can buy an additive than extends my unleaded petrol life for a year!
ClercLe 1 year ago
@ClercLe Try accelerating up a steep hill in high gear, and listen for a tinkling sound. Knocking, pre-ignition is sometimes called 'pinking' and this is perhaps a better description. Essentially it's an explosion in the cylinder rather than a burn. Diesels would always pink if they used a carburator, because all the mixture would ignite at the same time, but they don't, they're fuel injected, and burn progressively as the fuel is injected.
gamesbok 1 year ago
Ah sweet benzene - reminds me of a merry old Limmerick:
There once was a girl named Irene
Who drank only distilled kerosene
'Till she started absorbin'
A new hydrocarbon
And since then she's never benzene....
(applause) v*-bow-*v
TimTrimT 1 year ago 103
@TimTrimT I wish I could give you two thumbs-up for that!
ElveeKaye 1 year ago
How many models of molecules does the Professor have??
busterlanger 1 year ago
Wait around 1:50 you say the benzene has a single bond then a double bond (alternating around the molecule). i thought that all of the bonds were the same length so they cannot alternate and that there are delocalised electron fields above and below the molecule.
Lodgeinator 1 year ago
@Lodgeinator That is right i think they are just presenting the simplest model. In acutallity all the bonds are same lenght.
HaT223 1 year ago
The snowflake dog toy as a molecular model is classic.
ganymede36 1 year ago
Nowadays most schools use methylbenzene (PhCH3) or other benzene derivatives to do the nitration reaction. My school uses methyl benzoate (PhCOOCH3).
Quite envious that Prof could do this reaction with benzene. :P
bullets0000 1 year ago
@bullets0000 Here methylbenzene, or toluene, is also used in place of benzene. I believe xylene (dimethylbenzene) is an even better alternative, regarding safety and such.
Ulfin 1 year ago
@Perscriptions In Spanish the word for petrol is 'bencina' (pronounced: benz-EE-nuh), and yes, there is benzene in petrol.
eltotoX 1 year ago
Benzene is also found in Cigarettes.
BenjaminFranklin2u 1 year ago
Have you mentioned the distinctions between Alkanes, Alkenes and Alkynes?
TomMarAlem1987 1 year ago
This is what we just went over in Advanced Chemistry at my school. I really think this is awesome!
swedishgorilla1 1 year ago
What kind of CHIPs are on Nitro-benzene?
i450 1 year ago
Light the benzene ice with a match- make fire ice?
kcazzo69 1 year ago
What kind of CHIPs are on Nitro-benzene?
i450 1 year ago
Why Debbie's lab coat is always that dirty and messy? :-O
yiyifone 1 year ago
Comment removed
hobbit258 1 year ago
Frankly, I'd be more worried about accidentally drinking the gasoline or nearly 100% alcohol than just a trace of benzene.
safibn1 1 year ago
I have a question, according to a link from Youtube, there is a concern about soft drinks having benzene due to the reaction of x Bensoate (Na or K), and Citric Acid, which when both chemicals are in a soda (and they are!), and are exposed to heat or time, they convert to Benzene. The link sent you to a news article stating 2-4x the benzene levels considered safe for water are found in sodas. Is this reaction correct? What would cause it (ie how much time or heat?), etc?
zbret 1 year ago
@zbret The reaction is correct, although it could be an instable reaction, soft drinks have Sodium or Potassium benzoate in it, wich produces benzene and you ingest it, the reaction is not always certain, as you said it need unknow time and heat but it exists, but we should concern ourselfs more of what comes from Air pollution or products we use in the daily basis such as detergents,perfumes etc.
Draxis32 1 year ago
Do an episode for Lysergic acid diethylamide.
DaDaWgLLS 1 year ago
quick question.. do most molecules have a solid liquid and a gaseous state?
Wingers413 1 year ago
@Wingers413 All molecules have all three if you're willing to work hard enough.
tsumui 1 year ago
@tsumui well ya. but .. what about plasma? Can all elements exist in a state of plasma? I know my basic chem and physics,, was just wondering about the "extra states of matter" I.E. plasma and super fluids...
Wingers413 1 year ago
@Wingers413 yes, if the conditions are met, every element can become a plasma.
RitchieFelix 1 year ago
@RitchieFelix for plasma this might work (but it will be verey dificult for some elements) but superfuildity is something rather complicated and I am not sure if there are too much chemicals that can be made superfuid... the only one I know of is Helium...
AxtheDragon 1 year ago
cool video
coolliger 1 year ago
I should add a couple notes. The stutter/lurch the Professor described would more likely be caused by a miss - fuel NOT burning when it SHOULD. If this happens, you need to check your car's ignition timing or the spark plug gap.
As well, modern cars with electronic ignition can run on low-grade fuel without knocking, but this will still cause damage over time, and the performance will be poorer. Modern cars with Direct Injection can also cope by firing the fuel at the right time, like a Diesel.
JimPrower 1 year ago
Well, what happens to a car is that you get a noise under the hood called a 'knock," from the fuel pre-igniting before the piston gets to the top of the cylinder. Benzine decreases the ease of which which the fuel burns, meaning it only goes off when it's supposed to. High-performance cars have a very high Compression ratio, which, (as in a Diesel,) causes the fuel to ignite purely by the squeezing of the fuel/air mixture. If you have a knock, check your timing or put premium petrol in it.
JimPrower 1 year ago
Sorry, I meant Dr Kay.
genericmember1 1 year ago
Ohh :) I love it!
Konik107 1 year ago
I love these videos. When I was a prospective bachelors student I visited the University of Nottingham's chemistry department. But alas, at the time I despised Chemistry and decided that Chemistry all together was not the way to go.
These videos kind of make me wish I went. They have certainly re-ignited my interest. Also, I think I have a bit of a crush on Debbie and Professor Poliakoff has a great personality, they help.
genericmember1 1 year ago
Why was the label on the bottle covered up with black marker? There is only one structural form of pure benzene, and it was already drawn for us, so it's not like they censored the structure.
BlackSkullRacer613 1 year ago
Double Bond, SIngle Bond , Double Bond, SIngle Bond
Say that really fast when your tipsy lol
Thanks for all the great vids btw learned so much watching them :)
soulvibe2007 1 year ago
has the professor had a haircut? O:
MattDoesNotRock 1 year ago
I did a synthesis of dinitrobenzene at school. :-)
RoelMansje 1 year ago
oh cool, i was wondering why we always started w/ benzene derivatives in our organic lab class instead of actual benzene
dylz 1 year ago
When I took organic chemistry as an undergraduate in 1970 we used benzene by the GALLON for everything! It's an excellent solvent. We practically drank the stuff. And when we were finished with it, we simply dumped it down the drain.
GetMeThere1 1 year ago
yayyy organic chem!!!
AttackTofu 1 year ago
Mmmm.... benzene.
culwin 1 year ago
I like Debbie a lot, but I wish she'd either bleach that lab coat or get a new one.
luvtub 1 year ago
Benzine has one of the prettiest Lewis structures imo. Ever notice the more symmetrically pleasing they are the more dangerously toxic they seem to be?
quexalcoatl 1 year ago
@quexalcoatl The structures seen in the video are referred to as kekule structures, not lewis structures...two different things.
denChemiker 1 year ago
@denChemiker That's true. I'm no chemist. They're still nice looking and symmetrical in either.
quexalcoatl 1 year ago
I love your videos so much! I'm going to study chemistry :)
LeniInChains 1 year ago
I am still not quite sure how one would purify anything by crystallization. Can someone explain?
techguy33 1 year ago
@techguy33 Because it has a high freezing point, you can have benzene in another solvent, and precipitate it out after hot filtration. As it cools, crystals form, and then you can just get rid of the solvent and voila! nice pure benzene
hugiesrox 1 year ago
I didn't know about the traces of benzene in the lab alcohol (before you ask: I never drunk it!).
countvlad 1 year ago
randomviewer896 1 year ago
I love these videos. Great job professors and/or chemists!
kandastrike 1 year ago
I can't believe that the professor was allowed to make nitrobenzene at school. I never did anything that exciting.
biscuitfinger 1 year ago
I did this last year, the Kekulé structure and all. I found it very interesting with the delocalised pi-electron system.
MusashiShimmen 1 year ago
whats up with the water bottle collection? id like to hear about that.
4jonah 1 year ago 4
@4jonah i believe there has been a vid about that, i think it was the one where they answer the questions from the US kids?
munsking 1 year ago
@4jonah We have a video all about the The Professor's water bottle collection at our nottinghamscince channel
periodicvideos 1 year ago 5
@periodicvideos what is the name of the video? or could you post it as a response or something. its very difficult to find.
puretroubleman 1 year ago
That was a great video, I enjoyed it very much - I've learned a bit about aromatic compounds in organic chemistry at college and benzene somehow always managed to get my attention in a special way. Maybe because my teacher told us to think of its electronic cloud as a donut because of the electron delocalization. I also didn't know why these coumpounds were called "aromatic", but now I do. :D I'm looking forward to see more videos! Greetings from a bioengineering student from Portugal :)
Miyakayame 1 year ago
The term aromatic is also to do with the enhanced stability of the benzene ring and the fact it undergoes electrophilic substitution reactions rather than the addition reactions of the usual conjugated trienes.
philsaspiezone 1 year ago
'we found out now it's really carcinogenic' . You guys have got to be kidding. Awesome vid though!
jacoman1234567 1 year ago
Nitration of Benzene; now there's a reaction you'd not allowed to do in schools nowdays. I recall my Dad nitrated benzene during his A levels 30 or so years ago.
oOoxelAoOo 1 year ago
When my brother was about 6 or 7, he thought he would be a smart and take a swig of dad's beer that he had setting while he was working on his truck.
Unfortunately, the can had gas in it, not beer (I guess he was working on the carb?)
That was a pleasant experience. Almost as pleasant as the huge dose of chlorine gas i hit him with (accidentally) while playing with an old school freon leak detector, or watching him pass out after hitting two balloons worth of helium off my uncle's tig welder.
jcims 1 year ago
@jcims What the fuck is wrong with your family.
johnmacward 1 year ago
@johnmacward haha...we're both old and boring now, just hoping our offspring inherit their dads good fortune and their mothers brains
jcims 1 year ago
@jcims Ha ha!
johnmacward 1 year ago
4:34 . I swore she called the ice, mice.
eveningniteshade 1 year ago 15
@eveningniteshade "some ice" Lol, I thought the same thing!
Hlaford347 1 year ago
she said "some ice"
brenoakiy 1 year ago
@eveningniteshade "We'll put in someice"
someice -> some mice xD
vipersrules 1 year ago
@eveningniteshade for me it was quite like "so what we have here is just nice"
keepup32323 1 year ago
@tuva500 In Dutch it's even closer, fuel is "benzine". =)
FrostPegasus 1 year ago
CRAIG BENZINE
bigbookofnothing 1 year ago
I'm kinda disappointed the video didn't talk about how useful benzene is to synthesize new organic compounds :( although he did mention making nitro-benzene. He should of kept going and explaining different things that can be produced from it.
theway1990 1 year ago
German = "Benzin".
Sounds almost exactly the same as engl. "Benzene".
Patrickssj6 1 year ago
This has been flagged as spam show
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disast3r1 1 year ago 4
this might be a really basic chemistry question so excuse my lack of knowledge on the subject.. how did the chemists of the past they are speaking on know it had 6 carbons and 6 hydrogen atoms?
lejink 1 year ago 12
@lejink First they would have burned some benzene in excess oxygen and measured the ratio of CO2 to water vapor given off. That told them Benzene was made of equal parts H and C. After that, they could determine the number of molecules there are in a gram of C6H6 by applying the ideal gas law to some benzene vapor. Then they figure out how many CH groups it takes to equal that molecular mass.
Envergure 1 year ago
@lejink one simple way is to burn it - benzene will burn with a yellow, sooty flame due to higher carbon to hydrogen ratio (incomplete combustion), whereas alkanes (non-aromatic compounds) burn with a clearer flame (more complete combustion to water and CO2).
lordaxil 1 year ago
@lejink magic!
evando2006 1 year ago
@lejink im just guessing but mass spec maybe ?
theemacguy 1 year ago
@lejink I think it has something to do with the various bonds it has, such as what it bonds with and how difficult it is to get it to bond.
ViolenceFetish69 1 year ago
@lejink They probably burned it and measured the amount of product they got to work out the empirical formula
Trekkie0401 1 year ago