Cracking a hydrocarbon
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- Опубликовано: 10 фев 2011
- You can find instructions for this experiment at www.rsc.org/learn-chemistry/re...
Liquid paraffin (a mixture of alkanes of chain length C20 and greater) is vaporised and passed over a hot pumice stone catalyst. A gaseous product is obtained which is flammable and which will decolorise bromine water and acidified permanganate ions. The same apparatus and method can be used to dehydrate ethanol.
The longest 7 min video i have ever seen
lol yeah
True. But it was still useful tho
@@johnsamosa3927 thx for the reply
@@lucasvan8707 i agree
@@sullyvan151 youre welcome
POV: The legend Mrs Barnfield wants uses RUclips videos to demonstrate cus she's hip with the kids.
Honestly just here because I nearly fell asleep watching this in my science lesson because it was so relaxing 💀
POV: Mrs Barnfield has forced you to watch this video and summarise what it is about
😂😂😂😂
At least you got it right this time
Nah it’s a mrs bunting lmao
Can u send me ur write up boss
It’s not her, it was Mr Peanut
They allow for seperate pathways through which you go from the same reactants to products with less activation energy. Solid catalysts like platinum and palladium hold the molecules of the reactants down so they can react more easily, and they then push off the products, something very important for good catalysts. Cataysts need not be solid as long as they make for a mechanism in which they're not used up. Fast colliding particles in the appropriate spatial orientation lead to reactions.
Pumice isn't solid?
thanks mr hoyland. totally needed this today.
Why is porous pot catalyst used normally in this reaction? How exactly does it reduce the activation energy?
thank you for savinng my chemistry GCSE
does this mean that the silica gel powder from chromatography or a silica gel from shoe boxes can be used as catalyst?
Why is the catalyst heated strongly before the oil is warmed ? would evaporate too quickly ?
what is the catalyst used in industries in cracking? what did she say?
I loved it, your science is very amazing!
How the paraffin absorbed by the mineral cotton wool undergoes cracking to form these different organic compounds.
Link at the end of the video is unavaliable!
love the video.What a watch!!!Extremely exciting.thanks kiddos
Her voice makes me expect her any minute to start talking about the doctor and the Tardis.
Wait. Isn't mineral wool the name for asbestos?
Edit: Its not, but still not good to breath in
Thank you for posting this video!
Extremely useful! Thank you
Bare complicated words...
yo my kitty kat g
Thanks! It help a lot
I'm confused about the last conclusion made about the last tube: Is it alkane or alkene you meant? ALKANE with a carbon-carbon double bond is contradictory...
The text at 6:26 says alkene.
Ian Yang An alkane has only one carbon to carbon covalent bond where as an alkene will have 2 carbon to carbon covalent bond and therefore it is unsaturated as the carbon atoms aren't bonded to the maximum amount of atoms. this make it reactive and so able to decolourise bromine water.
gabriella ashong thank you!! 💪❤
Agree strongly with Stephen - a Bunsen valve is easy to make and adds safety. About 3cm of rubber tubing that fits over the end of the delivery tube. Make a longitudinal slit in the tubing with a scalpel, about 1cm long and then plug the end of the rubber tubing with a short length of glass rod. NB if using bits of broken stirring rods, be very careful as they will have sharp edges that are best removed by polishing the broken surfaces in a hot Bunsen flame.
I was wondering why there wasn't an anti-suckback assembly on the delivery tube
I was thinking the same, basically like a brake bleeder.
What gas is released?
Hi,
I intend to use ZSM-5 as catalyst for cracking Straight-run heavy naphtha (80-180 deg-C) to improve RONC.
Please advice me this idea is good or not?
What reactions will happen? What products will we receive?
Best regards,
Thanks!
I think you got your answer by now
@@sisyphus645 lmao
may I beg your pardon! what is the name of that catalyst, the one that looks like chips?
Pumice stone
her voice is so professional and Discovery channel like
Would this work with vegetable oil?
No
why do we use mineral wool, both instead of normal wool or no wool?
If cotton wool is used it may catch fire
cotton wool could combust partially and contaminate the product
@@bilbo_gamers6417 appreciate the response but 2 years too late, I’m studying chemical engineering at uni rn dude
@@xVENOMZx glad to help :)
I understand how catalysts of this sort act, but I don't understand how this works as the catalysts sits to the bottom so the parafin doesn't necesarily goes through the stones
What is the reason the alkanes are collected first before the alkenes?
Thanks
@K dogg Yes
That's because alkanes are single bonds and therefore are formed easier and come out first. Hopefully you see this even if I'm 4 years late
I dont really get the double bond thing.. is she saying that double bond solution comes with a liquid that when mixed w/ mineralized compound, will turn to colorless solution?
alkene means double bond
For this experiment my chem class used Aluminium Oxide as a catalyst. I do understand that the catalyst decreases the amount of energy required to break the Carbon-Carbon bonds. however, how does it do so? Thanks
pranavguitarist the catalyst lowers the activation energy, requiring a low amount of energy (heat) to break bonds between the carbons then break into smaller chains/ lengths of carbon thus producing derivatives of larger hydrocarbons
thanks for sharing, good video, I have a couple of doubts, how hot should it be...?
Why can't the catalyst and the paraffin be put together...? What happens if I put them together...?
using alumina as a catalyst has the same effect...?
Thank you for your help...
this was posted 12 years ago, but id be happy to help with your questions
Please and thank you, of course, I saw that the video is from a long time ago but it caught my attention, if you can help me with what temperature the catalyst must reach and why it must be separated from the paraffin, that would be great...
The catalyst provides a large surface area for the cracking reaction to occur. Saturating the catalyst (wetting it with the feed stock) lowers the temperature due to the (endothermic action of evaporation) and stops the reaction. The surface area of the catalyst has to remain at a high enough temperature and this can only occur when the feed stock in contact with the catalyst is a vapour. @@leifercontreras4949
but why cant we use cotton wool for this experiment?
i love cracking! (paraffin)
More of a meth person myself
@mayblue119 click cc at the bottom of the screen and click transcribe audio
U r magician !
I love how she says you need a compatent assistent XD
very nice
Awesome video. A very important petrochemical refinery cracking reaction in a test tube. Can anybody tell me what is difference between cracking and reforming? , as i often see the same type of catalyst and temp. are used in both cases and also product is sometimes similar.
GREAT VIDEO
Could you also test for the presence of unsaturated hydrocarbons by passing it through hydrogen and weighing it before and after with a precise enough scale?
You can test for it using bromine water
yeah
Very relevant experiment to enhance the knowledge on hydrocarbons
Is the pumice stone selected as a catalyst for its physical properties, or its chemical properties?
can we use this method to find adulteration of mineral oil in edible oil?
No. This is alkanes and alkenes, not lipids
Maybe using thin layer chromatography
thank you
omg dr wong, im ur biggest fan
Can anyone send me a write up
Bel pezzo di chimica!
Thats very interesting. Mam can you kindly give us the procedure of isolating N decane from paraffin
Ten years later,wow, it really helped me
Thanks for the video, but i didn't get an knowledge on how to separate the gases in those tube . To me i felt as if only one gas which was been released..help me mrs...
if your teacher asked you to make notes/summarise and you don't want to listen to the whole thing, click the three dots, then click 'open transcript'
didn't realise that lol, good eye!
Wow very knowledgeable
hello my question is:-pumice stone which is used to clean ankle of feet, can be used as a catalyst?
as in available in general store shop pumice stone is sold to smoothening ankle of leg,generally used by women.This type of pumice stone can be used as a catalyst?
Yes @rajat kumar singh
excellent video.. i wish you can ellaborate more on the function of the catalyst.. some good comments below though.
I'm speedrunning life right now
this is quality stuff here!
POV: Dr Bell sent a link on smhw and told you to watch 2 videos
hi there trident man productions
Her voice is so satisfying ❤
this is amazinggg!!!!
5:50 i sniff it fully when its not a dangerously chemical xd
i love her voice
why does suck back occur?
There is a drop in pressure in the boiling tube
Thank you mam
Both the bromine and the permanganate can oxidize the hydrocarbons if they have double bonds. Since these oxidated compounds are colourless and their formation depletes the colourful reactant, you can witness the colour change.
Eg: CH2=CH2 (colorless) + Br2 (orange) --> BrCH2-CH2Br (colorless)
[ethylene + bromine --> 1,2-dibromoethane]
Oxidated? I think you mean oxidized. I'm going to assume this was a brainfart, since you used the present temse, oxidize, properly. Either that, or perhaps English isn't your first language. But the chemistry checks out. No pseudoscience here.
Now that I think about it, I recall this was one of the first reactions I learned about. Reacting a halogen with an alkene to replace the double bond with a single bond and a halogen. It was so long ago, I can't recall the name of it. Maybe SN1. Or halogenation. I learned this before this video was even made, so the information has gotten a bit dusty on the shelves in my brain.
Gr8 video
POV: u wanna watch attack on Titan but a certain teacher makes u watch this instead 🤬😔
Same
😂
*Titan
same ;/
im more a full metal alchemist fan ngl
thank you so much. this is a great video!
just so you know miss Kennedy, no one listened to this :)
Great
*competent student*
Nice
Isn't it illegal to produce crack in the UK?
Not what I expected
Burner, take care...
Wooooooow
you need to activate the surface of the catalyst first.
Stop seducing me with your knowledge of organic chemistry
"Avoid suckback" needs to be on a T-shirt!
useful video despite the CRISP 240p
Thanks for the help
did it
thanks for posting ...
the transcript from 2:06 - 2:12 :')
Very interesting experiment and wonderful execution.
where is your lab GLOVE?
Staaaaa of david
Personally I thought that was hot as hell.
Nice video!
If you want to learn more about the uses of oil in our everyday life, check out Fuelling Europe’s Future channel. For those who are interested there is also an interactive animation hosted on our website.
asmr
my science teacher says you need to us ceramic wool not mineral wool
Why did she not wear gloves?
because there is no need.... not sure why everyone on youtube thinks gloves is essential for every single thing in chemistry....
Because they can ignite
Better question: why is she wearing jewelry in the lab?
Juss you wayt, 'Enry 'Iggins, juss you wayt!
Bung? I call them stoppers (rubber stopper or glass stopper).
@HCHalexfan its mineral wool and you can use cotton wool too
Because I'm definitely gonna need to know this, thank you so much government I'll use this every single day of my fucking life :)
You chose A-Level chemistry, mate...
I’m 15 I get forced to learn this shit
@@daisyniamh4493 same
Bbechstein!
This was extremely helpful, thank you very very much ^,^
And at 3:28...
That's the best!
"and you're going to heat a palestine"
She said "and you're going to heat the _pumice stone_ ", not _palestine.._
@@jhyland87 LOL THAT COMMENT WAS FROM 6 YEARS AGO WHY REPLY NOW
@@djay3531 callete all caps anti intellectual