Ifailedagain
Badges: 8
Rep:
?
#1
Report Thread starter 2 years ago
#1
So I’m currently doing catalytic and thermal cracking, but I’m a bit stuck with it. So if catalytic cracking produces branched alkanes ,cyclic alkanes and aromatic hydrocarbons, what would the equation be to form the cyclo alkane of heptane? If its c7h16 = what cyclo alkane would be formed ( if this makes sense, I’m doing my best to explain it)
0
reply
mafk80
Badges: 14
Rep:
?
#2
Report 2 years ago
#2
(Original post by Ifailedagain)
So I’m currently doing catalytic and thermal cracking, but I’m a bit stuck with it. So if catalytic cracking produces branched alkanes ,cyclic alkanes and aromatic hydrocarbons, what would the equation be to form the cyclo alkane of heptane? If its c7h16 = what cyclo alkane would be formed ( if this makes sense, I’m doing my best to explain it)
Catalytic cracking has the advantage of requiring a lower temperature (800K) and requires a Zeolite catalyst.
Thermal cracking requires heating larger alkanes at a high temperature (> 1200K), which provides enough energy to break C-C bonds.

Thermal cracking tends to produce a higher number of alkenes compared to catalytic cracking.

In all cases of cracking, the end result is the production of short-chain alkanes and short-chain alkenes. I dont think cracking produces branched chains.

Branched chain alkenes are produced from straight chain alkanes in the process of "reforming". i.e. when hexane is heated under pressure in the presence of a catalyst, you get benzene + 4H2.
0
reply
ChemistryWebsite
Badges: 10
Rep:
?
#3
Report 2 years ago
#3
(Original post by mafk80)
Catalytic cracking has the advantage of requiring a lower temperature (800K) and requires a Zeolite catalyst.
Thermal cracking requires heating larger alkanes at a high temperature (> 1200K), which provides enough energy to break C-C bonds.

Thermal cracking tends to produce a higher number of alkenes compared to catalytic cracking.

In all cases of cracking, the end result is the production of short-chain alkanes and short-chain alkenes. I dont think cracking produces branched chains.

Branched chain alkenes are produced from straight chain alkanes in the process of "reforming". i.e. when hexane is heated under pressure in the presence of a catalyst, you get benzene + 4H2.
Benzene is a branched chain alkene??
This is news to me.
0
reply
mafk80
Badges: 14
Rep:
?
#4
Report 2 years ago
#4
(Original post by TutorsChemistry)
Benzene is a branched chain alkene??
This is news to me.
Youre right! Benzene is not technically a cyclic alkene. I should have clarified that in the example I gave for reforming of Hexane. I was trying to make a point that reforming produces branched hydrocarbons, whereas cracking produces short unbranched hydrocarbons. Do you agree? If you think otherwise, please let me know in case my concept is not 100% clear.

Cheers!
0
reply
ChemistryWebsite
Badges: 10
Rep:
?
#5
Report 2 years ago
#5
(Original post by mafk80)
Youre right! Benzene is not technically a cyclic alkene. I should have clarified that in the example I gave for reforming of Hexane. I was trying to make a point that reforming produces branched hydrocarbons, whereas cracking produces short unbranched hydrocarbons. Do you agree? If you think otherwise, please let me know in case my concept is not 100% clear.

Cheers!
I think the clarification required is "how does it answer the OP's question?"
0
reply
mafk80
Badges: 14
Rep:
?
#6
Report 2 years ago
#6
(Original post by TutorsChemistry)
I think the clarification required is "how does it answer the OP's question?"
Well, the problem in my interpretation lies in the fact that I am unable to see the link between cracking and branched-chain alkanes, which is why I was unable to directly answer the OP's question. Since you're the Chemistry Tutor perhaps you can help him by answering his question rather than fixating on the imperfections in my statements.
0
reply
ChemistryWebsite
Badges: 10
Rep:
?
#7
Report 2 years ago
#7
(Original post by mafk80)
Well, the problem in my interpretation lies in the fact that I am unable to see the link between cracking and branched-chain alkanes, which is why I was unable to directly answer the OP's question. Since you're the Chemistry Tutor perhaps you can help him by answering his question rather than fixating on the imperfections in my statements.
Sorry to "fixate" on the incorrect answers. I think we owe it to OP's to point out when an answer is misleading or downright wrong.

As I haven't taken the time to consider this question deeply enough to give a clear and accurate response I haven't answered the OP question.
To be clear, I have chosen not to just write something I think I know that is a bit like what the OP asked about. That's not why I am here.
But I am here to point out where things are wrong. It's not personal. Up 'til yesterday no-one reacted as if it were personal.
0
reply
mafk80
Badges: 14
Rep:
?
#8
Report 2 years ago
#8
(Original post by TutorsChemistry)
Sorry to "fixate" on the incorrect answers. I think we owe it to OP's to point out when an answer is misleading or downright wrong.

As I haven't taken the time to consider this question deeply enough to give a clear and accurate response I haven't answered the OP question.
To be clear, I have chosen not to just write something I think I know that is a bit like what the OP asked about. That's not why I am here.
But I am here to point out where things are wrong. It's not personal. Up 'til yesterday no-one reacted as if it were personal.
I might have over-reacted. I'm majorly sleep deprived and I'm under a considerable amount of stress preparing for my medical school assessment day. Apologies! Now, I better get back to understanding the biochemistry of Alkaptonuria. I hope you are able to help the OP out. Peace!
0
reply
Pigster
Badges: 19
Rep:
?
#9
Report 2 years ago
#9
Just to stick my oar in, but isn't the process whereby straight chains are converted into branched/cyclical ones called reforming, rather than cracking?
0
reply
Medic Mind
Badges: 15
Rep:
?
#10
Report 2 years ago
#10
(Original post by mafk80)
I might have over-reacted. I'm majorly sleep deprived and I'm under a considerable amount of stress preparing for my medical school assessment day. Apologies! Now, I better get back to understanding the biochemistry of Alkaptonuria. I hope you are able to help the OP out. Peace!
Hi there! It is very important to get plenty of sleep before your exam! We specialise in medical school applications and assessments pertaining to them. What assessment is this? We can provide expert advice, mentoring and tutoring regarding these assessments so feel free to contact us!

If you would like to read more about this topic and many other topics, check out our resources covering: FULL revision notes of Biology, Chemistry and Economics written by a tutor who attained nearly full UMS in these subjects (all A*s), past paper questions and model answers compiled by topic - we believe that making notes based on model answers, memorising and understanding them consolidates your knowledge, and confidence in answering various different question types given to you in the exam! That’s how our expert tutors have all attained As and A*s in their A Levels!


Resources: www.medicmind.co.uk/resources


If you would like more support in your studies, feel free to contact us - do not hesitate to ask us questions! We provide 1-1 tutoring for A Level and GCSE Students, and A Levels covering: Biology, Chemistry, Physics, Mathematics, Further Mathematics, Economics and more, from as little as £25 per hour!


All the best!


Dhaval N - Medic Mind Tutor

Best UK Medical Startup 2017

www.interviewcourse.co.uk
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Are you travelling in the Uni student travel window (3-9 Dec) to go home for Christmas?

Yes (123)
28.28%
No - I have already returned home (58)
13.33%
No - I plan on travelling outside these dates (86)
19.77%
No - I'm staying at my term time address over Christmas (40)
9.2%
No - I live at home during term anyway (128)
29.43%

Watched Threads

View All