AS OCR chemistry B (SALTERS) F331 on the 15th may 2012
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012Disadvantages of biofuels: Take up a lot of space that could be used for crops, reduces biodiversity, CO2 emissions in manufacture(Original post by sunny_veggies)
Could someone tell me what disadvantages of biofuels and hydrogen the mark scheme accepts?? Thanks
Hydrogen - highly flammable, needs to kept under high pressure -
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012Thankyou sooo much, Good luck!!(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
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012oh thank god im terrible at it(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
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012Yes, HERE is the spec.(Original post by vicky8761)
conditions and reagents, thats f332 right? -
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012No we don't, not on OCR(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
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012yes(Original post by Salmonidae)
Reforming = Cycloalkane and Hydrogen
Craking = Alkane and Alkene
Isomerisation = Branched chain.
Is that all correct?
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 -
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012Yes they are(Original post by randomfatguy)
Electron configurations are in F331 right?
Simply CnH2n, if you think about it ever carbon is bonded to another two carbons so only has space for 2 hydrogens(Original post by dongonaeatu)
what is the formula of a cycloalkene? as in cn...
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012no that is wrong(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
it is cnh2n-2
cyclopentene is c5h8 -
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012good luck and god bless(Original post by dirrane)
Good luck everyone, i am getting ready now and off to school
hope it is an easy paper -
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Re: AS OCR chemistry B (SALTERS) F331 on the 15th may 2012You too, just hopped on the train on me phone and revision cards(Original post by dirrane)
Good luck everyone, i am getting ready now and off to school
hope it is an easy paper
GOOD LUCK EVERYONE - NAIL THIS CHEMISTRY
Personally i hate the subject but its crunch time!
