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AS OCR chemistry B (SALTERS) F331 on the 15th may 2012

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Could someone tell me what disadvantages of biofuels and hydrogen the mark scheme accepts?? Thanks
Reply 61
Original post by dirrane
That was Beautifully put together mate:smile:


haha thanks, good luck!!
Reply 62

Original post by sunny_veggies
Could someone tell me what disadvantages of biofuels and hydrogen the mark scheme accepts?? Thanks


Disadvantages of biofuels: Take up a lot of space that could be used for crops, reduces biodiversity, CO2 emissions in manufacture

Hydrogen - highly flammable, needs to kept under high pressure
Original post by bertiejess



Disadvantages of biofuels: Take up a lot of space that could be used for crops, reduces biodiversity, CO2 emissions in manufacture

Hydrogen - highly flammable, needs to kept under high pressure


Thankyou sooo much, Good luck!! :smile:
Reply 64
Original post by Salmonidae
Yes that stuff is in either F332 or you're on the wrong thread for your exam sylabus, will not find anything on that in F331 :smile:


oh thank god im terrible at it
Reply 65
Guys remember to be able to spell the word heterogeneous catalyst:wink:
Reforming = Cycloalkane and Hydrogen
Craking = Alkane and Alkene
Isomerisation = Branched chain.

Is that all correct?
Reply 67
conditions and reagents, thats f332 right?
Original post by vicky8761
conditions and reagents, thats f332 right?


Yes, HERE is the spec.
Reply 69
Do we have to wait till midnight again?
mann i cant wait that long, cos i got an exam at 9 in the blooody morning:angry:
Original post by dirrane
Do we have to wait till midnight again?
mann i cant wait that long, cos i got an exam at 9 in the blooody morning:angry:


No we don't, not on OCR :smile:
Original post by Salmonidae
Reforming = Cycloalkane and Hydrogen
Craking = Alkane and Alkene
Isomerisation = Branched chain.

Is that all correct?


yes

reforming produces cycloalkanes and arenes and hydydrogen

isomerisation creates branched chain isomers by heating straight chain alkanes with a platinum catalyst on inert aluminium oxide.

2 forms of cracking- thermal and catalytic cracking

thermal- high temp 100 celsius and high pressure makes mostly alkenes

catalytic- makes mostly motor fuels and aromatic hydrocarbons. uses a zeolite catalyst at a slight pressure and 450 celsuis
Reply 72
Original post by Salmonidae
No we don't, not on OCR :smile:


yeahhhhhhhhhhhh thank you
Electron configurations are in F331 right?
what is the formula of a cycloalkene? as in cn...
Original post by randomfatguy
Electron configurations are in F331 right?


Yes they are

Original post by dongonaeatu
what is the formula of a cycloalkene? as in cn...


Simply CnH2n, if you think about it ever carbon is bonded to another two carbons so only has space for 2 hydrogens :smile:
Original post by Salmonidae
Yes they are



Simply CnH2n, if you think about it ever carbon is bonded to another two carbons so only has space for 2 hydrogens :smile:


no that is wrong
it is cnh2n-2

cyclopentene is c5h8
Reply 77
Good luck everyone, i am getting ready now and off to school:biggrin::biggrin:
hope it is an easy paper
Original post by dirrane
Good luck everyone, i am getting ready now and off to school:biggrin::biggrin:
hope it is an easy paper


good luck and god bless
Original post by dirrane
Good luck everyone, i am getting ready now and off to school:biggrin::biggrin:
hope it is an easy paper


You too, just hopped on the train on me phone and revision cards

GOOD LUCK EVERYONE - NAIL THIS CHEMISTRY

Personally i hate the subject but its crunch time!

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