OCR B F335 - Chemistry by Design - 13th June 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: OCR B F335 - Chemistry by Design - 13th June 2012A2 revise revision guide?...and what page mate(Original post by Bi0logical)
If you have the OCR Salters revision guide, there's a page with a list of synoptic stuff u need to know.
It's mainly the basics; electron config, different types of bonding, shapes, affects of catalyst/rate, etc etc -
Re: OCR B F335 - Chemistry by Design - 13th June 2012page 82(Original post by master_blaster66)
A2 revise revision guide?...and what page mate
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Re: OCR B F335 - Chemistry by Design - 13th June 2012
Buffers in action;
Carbon Dioxide is dissolved in oceans and limestone rocks (mainly calcium carbonate) act together as a buffering system. The "carbonic acid" produced acts as a weak acid and the limestone acts as an anion (CO32-) sink.
This means that as atmospheric CO2 increases and dissolves to form carbonic acid, the pH can be maintained. -
Re: OCR B F335 - Chemistry by Design - 13th June 2012can you post a link to the paper and mark scheme so i can help?(Original post by minip12qss)
for the last question on the jan 2012 F335 paper does anyone know how to get the pH.
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Re: OCR B F335 - Chemistry by Design - 13th June 2012
F335 Jan 12 MS.pdfF335 Jan 12.pdf
I think its attached btw its the last question -
Re: OCR B F335 - Chemistry by Design - 13th June 2012i remember this was a tough question, i was doing this pastpaper a few days ago(Original post by minip12qss)
F335 Jan 12 MS.pdfF335 Jan 12.pdf
I think its attached btw its the last question -
Re: OCR B F335 - Chemistry by Design - 13th June 2012did you work out how to do it(Original post by master_blaster66)
i remember this was a tough question, i was doing this pastpaper a few days ago -
Re: OCR B F335 - Chemistry by Design - 13th June 2012
46g of Methanoid acid vapor are found to occupy 16dm3 at 120degrees and room pressure.
Suggest an explanaition for these data. Include full structural formula in your answer.
One mole of gas molecules of a gas at 120degrees and room pressure occupies 32dm3 -
Re: OCR B F335 - Chemistry by Design - 13th June 2012This one got me. It's double what you expect from a methanoic acid molecule, so there has to be two, joined by hydrogen bonds... and you have to know that you should draw a diagram of two molecules hydrogen bonded.(Original post by Bi0logical)
46g of Methanoid acid vapor are found to occupy 16dm3 at 120degrees and room pressure.
Suggest an explanaition for these data. Include full structural formula in your answer.
One mole of gas molecules of a gas at 120degrees and room pressure occupies 32dm3 -
Re: OCR B F335 - Chemistry by Design - 13th June 2012I did the paper you told me to do, I got 94, I made loads of silly mistakes though... It was a fairly tough paper, but nothing spectacularly hard.(Original post by master_blaster66)
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Re: OCR B F335 - Chemistry by Design - 13th June 2012ooo I was very close, I wrote something about only 1 mole of methanoic acid occupying 16dm3, because rfm 46/46 = 1.(Original post by navarre)
This one got me. It's double what you expect from a methanoic acid molecule, so there has to be two, joined by hydrogen bonds... and you have to know that you should draw a diagram of two molecules hydrogen bonded.
that is one of the most difficult question I came across, it's not actually hard, you just dont know what its asking you and they dont make it clear
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Re: OCR B F335 - Chemistry by Design - 13th June 2012Nothings hard for you bro(Original post by Ilyas)
I did the paper you told me to do, I got 94, I made loads of silly mistakes though... It was a fairly tough paper, but nothing spectacularly hard.
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Re: OCR B F335 - Chemistry by Design - 13th June 2012Exactly. You just have to guess that they want you to show two hydrogen bonded methanoic acid molecules. I'd never seen a question like that before, but tbh, at least we've seen it now, so if in the exam they ask a similar one, we'll have some clue.(Original post by Bi0logical)
ooo I was very close, I wrote something about only 1 mole of methanoic acid occupying 16dm3, because rfm 46/46 = 1.
that is one of the most difficult question I came across, it's not actually hard, you just dont know what its asking you and they dont make it clear
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Re: OCR B F335 - Chemistry by Design - 13th June 2012So it's basically all of AS knowledge except some specific detail relating to certain topics (Developing fuels etc).(Original post by Bi0logical)
If you have the OCR Salters revision guide, there's a page with a list of synoptic stuff u need to know.
It's mainly the basics; electron config, different types of bonding, shapes, affects of catalyst/rate, etc etc
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Re: OCR B F335 - Chemistry by Design - 13th June 2012exactly that(Original post by Iepnauy)
So it's basically all of AS knowledge except some specific detail relating to certain topics (Developing fuels etc).