OCR A2 Chemistry Unit 5, F325 15th June 2015

Reply 1380

Dr. Django

12

Original post by Baloney26

Which questions do you mean? :s

The long calculation questions at the end of most papers where they give info wth various different steps.

Reply 1381

Captain Anonymous

14

To work out CAP UMS score for f322, for June 2014 do I do this?

Difference of A boundary and B boundary x2. Add this onto the A boundary?

So 74-64 = 10 x 2 = 20

74 + 20 = 94?
So, 150/150 is equal to 94 raw marks?

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Reply 1382

s.c.a1

10

does anyone have any buffer questions worksheets with answers that they can send me. ive pretty much done all the papers now but the buffer questions one time i get right and the next i don't :frown:

cant risk to get it wrong on the exam

Reply 1383

Baloney26

9

Original post by Captain Anonymous

To work out CAP UMS score for f322, for June 2014 do I do this?

Difference of A boundary and B boundary x2. Add this onto the A boundary?

So 74-64 = 10 x 2 = 20

74 + 20 = 94?
So, 150/150 is equal to 94 raw marks?

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I convert mine to ums by dividing the raw mark a boundary (74) by the ums for an a, 120 giving me a conversion factor lol 0.617 then times this by 150 which gives me 92.5 so round up to 93 but there's only one mark in it

Reply 1384

Captain Anonymous

14

Original post by Baloney26

I convert mine to ums by dividing the raw mark a boundary (74) by the ums for an a, 120 giving me a conversion factor lol 0.617 then times this by 150 which gives me 92.5 so round up to 93 but there's only one mark in it

I guess it works for unit 2 exams although, for unit 1. If the A boundary is 49 or higher you'll need 60+ for full ums. I'll stick with my method, thanks anyway

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Reply 1385

Straighthate

2

do we have to know ALL the transition metal ion colours?
that paper with the vanadium titration, if you didnt know that V2+ was purple you would have really struggled
i thought we only had to know Co2+, fe2+ and 3+ and Cu2+

Reply 1386

adeniszczyc

1

For anyone revising for this unit, I'm produced notes for OCR Chemistry F325 and F324 with diagrams/definitions on my revision website: http://revise.im/chemistry. I hope they can be useful to you! :smile:

Reply 1387

Captain Anonymous

14

Original post by Straighthate

do we have to know ALL the transition metal ion colours?
that paper with the vanadium titration, if you didnt know that V2+ was purple you would have really struggled
i thought we only had to know Co2+, fe2+ and 3+ and Cu2+

That's what I thought, not sure. Your best bet is to know the ones they say in the spec

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Reply 1388

Straighthate

2

Original post by Captain Anonymous

That's what I thought, not sure. Your best bet is to know the ones they say in the spec

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the spec doesnt actually mention any colours

Reply 1389

Lau14

11

Original post by Straighthate

the spec doesnt actually mention any colours

"describe, including ionic equations, the simple precipitation reactions and the accompanying colour changes of Cu2+(aq), Co2+(aq), Fe2+(aq) and Fe3+(aq) with aqueous sodium hydroxide; " at top of page 60 and some more halfway down that page, in the right hand column :smile:

Reply 1390

TheLegalDealer

9

Original post by Captain Anonymous

That's what I thought, not sure. Your best bet is to know the ones they say in the spec

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you only have to know the colour changes mentioned in the specification I've seen the question that you referred to but I think it tells you that V2+ ions are violet so you should already know that manganate ions are purple therefore answering by saying that it would be hard to know the endpoint because the colour changes are similar

So basically , you don't need to know all the transition metal ion colours just the ones in the spec

Reply 1391

Captain Anonymous

14

Original post by TheLegalDealer

you only have to know the colour changes mentioned in the specification I've seen the question that you referred to but I think it tells you that V2+ ions are violet so you should already know that manganate ions are purple therefore answering by saying that it would be hard to know the endpoint because the colour changes are similar

So basically , you don't need to know all the transition metal ion colours just the ones in the spec

Which is what I said...

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Reply 1392

letsbehonest

15

Sat this exam last year - the best advice I can give to anyone is to do ALL the past papers twice, do all the exam questions in the textbook, do all the relevant legacy questions, use a-levelchemistry.co.uk and if you have the calculation in AS/A2 chemistry textbook (holy grail book) then use that!

Reply 1393

Yua

14

Original post by letsbehonest

Sat this exam last year - the best advice I can give to anyone is to do ALL the past papers twice, do all the exam questions in the textbook, do all the relevant legacy questions, use a-levelchemistry.co.uk and if you have the calculation in AS/A2 chemistry textbook (holy grail book) then use that!

what did you end up getting /150

Reply 1394

User1686961

12

Original post by letsbehonest

Sat this exam last year - the best advice I can give to anyone is to do ALL the past papers twice, do all the exam questions in the textbook, do all the relevant legacy questions, use a-levelchemistry.co.uk and if you have the calculation in AS/A2 chemistry textbook (holy grail book) then use that!