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OCR Chemistry F322~ 4th June 2013~ AS Chemistry

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Also can someone please explain the major points of green chemistry?


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Original post by beautywithbrains
Which had been the hardest paper so far?


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jan 2011 had the lowest boundary for an A, 71
Reply 1522
Avatar for lucy3003
lucy3003
Hey can anyone explain how to do question 1(e)(iii) from the june 2010 paper?
Original post by beautywithbrains
Also can someone please explain the major points of green chemistry?


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past papers and mark schemes are the best thing to look at for green chemistry
Reply 1524
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lucy3003
Also does anyone know why for June 10 paper 1(e)(v) it asks to comment on percentage yield and atom economy but then on mark scheme it says 'ignore comments on percentage yield'?!!
Original post by needtosucceed=)
past papers and mark schemes are the best thing to look at for green chemistry


Ok thanks!


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Reply 1526
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lucy3003
Original post by needtosucceed=)
moles is mass/molar mass
so 3.6x10^5/26

but it says 3.6x10^5 dm3 made each day not grams?
Original post by lucy3003
Hey can anyone explain how to do question 1(e)(iii) from the june 2010 paper?


your given the volume of c2h2 so number of moles = volume/24

so 3.6x10^5/24 = 15000
Original post by lucy3003
but it says 3.6x10^5 dm3 made each day not grams?


sorry ignore that post.
Reply 1529
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lucy3003
Original post by needtosucceed=)
your given the volume of c2h2 so number of moles = volume/24

so 3.6x10^5/24 = 15000

Ooohhh yes of course thank you!!
Original post by lucy3003
Also does anyone know why for June 10 paper 1(e)(v) it asks to comment on percentage yield and atom economy but then on mark scheme it says 'ignore comments on percentage yield'?!!


yea i was wondering this too, pretty stupid really
Reply 1531
Avatar for Daniel__
Daniel__
Anyone mind helping me with this question about determining displayed formulas of organic compounds; 2 (e) http://www.ocr.org.uk/Images/131287-question-paper-unit-f322-chains-energy-and-resources.pdf

MS: http://www.ocr.org.uk/Images/135164-mark-scheme-unit-f322-chains-energy-and-resources-june.pdf
Original post by Daniel__


the products will be either an aldehyde or carboxylic acid

so for each product oxidise both ends. the mark scheme allows a mixture of only oxidising one end but you might as well do the same thing on each side.
Reply 1533
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SAS18
10
Original post by Daniel__


If it is refluxed then it would oxidise completely and form carboxylic acids. now here you draw as if both alcohols have formed into carboxylic acids or just one.
likewise, if distilled, then it partially oxidises and aldehyde is formed. as above it can be on both or just one alcohol.
Reply 1534
Avatar for Daniel__
Daniel__
Original post by needtosucceed=)
the products will be either an aldehyde or carboxylic acid

so for each product oxidise both ends. the mark scheme allows a mixture of only oxidising one end but you might as well do the same thing on each side.


If it is refluxed then it would oxidise completely and form carboxylic acids. now here you draw as if both alcohols have formed into carboxylic acids or just one.
likewise, if distilled, then it partially oxidises and aldehyde is formed. as above it can be on both or just one alcohol.


Thanks.
Reply 1535
Avatar for Gotzz
Gotzz
13
Original post by SAS18
what boards are you with?
mine are wjec for bio, ocr for chem (obviously) an aqa for physics


Mine are all OCR A
Can someone explain qu 2c)ii) on the jan 11 paper


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Original post by beautywithbrains
Can someone explain qu 2c)ii) on the jan 11 paper


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the equations actual moles/theoretical moles x100

so theoretical = 6.25/molar mass of butan-1-ol

actual = 6.57/molar mass of butylethanoate

divide actual answer by theoretical answer then x100
Does a ketone form under reflux? Or can it form through gentle heating and then distilling as with an aldehyde?


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Original post by Polypocus
Does a ketone form under reflux? Or can it form through gentle heating and then distilling as with an aldehyde?


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I think its reflux :smile:

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