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NUFFIELD Chemistry AS & A2 exams thread

The AEA looks like a LOT of challenge. But the application is good practice, even if I haven't got the faintest idea (very likely).

What sort of things are you thinking of reading about this summer? Generally reading around the subject or focusing on specific areas of chemistry?

The highest grade boundaries for an A that I remember are 49 and 50 out of 60 - both were for Unit 3 (the practical element) I think. Which scared me...

Reply 21

fblade

14

hey im doin Unit 1 and Unit 2 for Nuffield, I got 54/60 for Unit 3.

I've forgotten how to calculate the percentage yield, does anybody know how to do it?

Reply 22

firestone

9

Hey

Percentage yield = mass of product obtained/theoretical yield x 100%

Hope that's it...

Reply 23

man_in_black

OP

omgomgomgomgomgomgomgomgomg that appendix B is fantastic, keep it quiet, we don't want other people knowing about this. :wink:

The only thing is it doesn't give the colours of different metal ions when they form precipitates. e.g. in topic 1 these are some of the inorganic ppt's:

Copper (II) chloride, CuCl2.2H2O: blue crystals

Iron(II) sulphate, FeSO4.7H2O: pale green crystals

Magnesium carbonate, MgCO3: white powder

Iron(III) nitrate, Fe(NO3)3.9H2O: pale yellow-brown crystals

Potassium carbonate, K2CO3: white powder

Iron(III) oxide, Fe2O3: red-brown powder

Do you think we need to know these? And other colour changes like in the thermal decomposition of ammonia dichomate when the Cr6+ ion is reduced to the green Cr3+ ion.

Reply 24

mike89

What do u ppl think about the summary. To be honest its easy but i seem to spend too much time on it over 30mins! :eek:

Also, in the appendix it has hydrocarbon colours-do we need to know all of them because the book does not mention them and i have seen only one qns on it out of all the papers i have done??? :confused:

Reply 25

Kentish Man

7

man_in_black

Copper (II) chloride, CuCl2.2H2O: blue crystals

Iron(II) sulphate, FeSO4.7H2O: pale green crystals

Magnesium carbonate, MgCO3: white powder

Iron(III) nitrate, Fe(NO3)3.9H2O: pale yellow-brown crystals

Potassium carbonate, K2CO3: white powder

Iron(III) oxide, Fe2O3: red-brown powder

I never knew these. I don't think you have to.

Reply 26

man_in_black

OP

mike89

What do u ppl think about the summary. To be honest its easy but i seem to spend too much time on it over 30mins! :eek:

By summary do you mean section B of the exam? It's not too bad, just make sure you read the text thoroughly and like you say, don't spend too long on it.

mike89

Also, in the appendix it has hydrocarbon colours-do we need to know all of them because the book does not mention them and i have seen only one qns on it out of all the papers i have done??? :confused:

...It doesn't mention any hydrocarbons at all. Unless you mean the halogens in hydrocarbon solvents?

Reply 27

fblade

14

why do even have to do a summary of an essay, its got nothing to do with chemistry, apart from the topic of the text

Reply 28

pucca_8

I have Unit 2 on the 7th , then 19th I have unit4 and Unit5, Last one on the 26th for Unit 6
my teacher advice us spen 45 mins on Section B in Unit 2 paper, then get your time guys.

Reply 29

firestone

9

lol

Thanks for the precipitate colours! Though I haven't come across many of them til now.

Thermal decomposition of ammonium dichromate? Really worried now...can't remember even doing that reaction - which topic was it in?

Yeah we need to know the colours of halogens in hydrocarbon.

The summary is the last thing anyway so hopefully it won't take up all the time. Apparently it's meant to test our ability to draw out information and...summarise.
But I always end copying out the text word from word anyway. Does anyone actually change the wording?

Reply 30

man_in_black

OP

firestone

Thermal decomposition of ammonium dichromate? Really worried now...can't remember even doing that reaction - which topic was it in?

Topic 1, page 4 of the students' book... it's the 'volcano reaction'. That's what I mean about unit 1 being full of annoying reactions that are too numerous to remember. Comparatively I don't think there's much to Unit 2 (except topic 6 and 8).

firestone

The summary is the last thing anyway so hopefully it won't take up all the time. Apparently it's meant to test our ability to draw out information and...summarise.
But I always end copying out the text word from word anyway. Does anyone actually change the wording?

I use the same wording too. I don't like to miss out words just in case one or two of them are really important. I'm hoping it's alright to do that. Are there any websites that give advice on the summary? Revision guides don't mention it....

Reply 31

man_in_black

OP

Actually forget what I just said about topic 8 being hard.... there are very few reactions we need to know there. Just...

Experiment 8.2 The properties of some alkanes

Experiment 8.4a Extracting limonene from oranges by steam distillation

Experiment 8.4b The reactions of the alkenes

Compare that with topic 6....

Experiment 6.1 The extraction of iodine from seaweed

Experiment 6.2 The reactions between halogens and halide ions

Experiment 6.4 Some reactions of the halides

Experiment 6.5 The reactions of the halogens with alkalis

Experiment 6.6 Some reactions of sodium chlorate(I)

Experiment 6.7 Some reactions of the potassium halates(V)

Experiment 6.8a The preparation of potassium iodate(V)

Experiment 6.8b The reaction between iodine and sodium thiosulphate

Experiment 6.8c To determine the purity of samples of potassium iodate(V)

Reply 32

Gregorian IV

8

I've got 58/60 in my unit 3.

I'm pretty surprised that some people are doing Unit 1...or are you resitting them?

When I did unit 1, it was rather easy. It didn't mention the volcano reaction or much of topic 1, if i remember rightly.

There was a big-ish question on the graphs of ionisation and why is the shape of it significant and so on.

Someone said something about hess' cycles earlier. Apparently, the only ones they will ask you to construct are one where you put the elements at the bottom and then you draw lines up to the 'reaction line'. But she may be wrong.

Topic 6 reactions are quite difficult to learn..i'll admit that but some of them are quite similar and its just remembering patterns.

In my opininon, i think that the unit 2 test may be easier than unit 1, as topic 9 is unbelievably short, topic 10 is very similar to topic 8, and topic 7 isn't too bad to learn.

However, what's with section B! I took chemistry not English. That's where im gonna lose most of my marks.

Reply 33

*Emily*

1

firestone

I'm dreading a question like,

"Describe the procedure of the preparation and purification of cyclohexene from cyclohexanol" - I don't know it at all.

Does anyone know whether we're expected to know anything about the "background reading" sections? I've hardly read any of them because they don't look that relevant...

By the way, just out of interest - what do you think about the syllabus/text book?

you dont need to know the content for AS for the background readings, however, in A2 we are supposed to use them to supplement your knowledge of the chapters or sth, and in the synoptic you may get asked questions that relate to one of these bg readings, and you need to know where to find the answer, for example thermosetting plastics or whatever!

my chemistry teacher is amazing!! seriously!! she's sooo enthusiastic about it, and teaches it in a really good way to understand, we hardly need to look at the book in lessons! she just has this drive for it and she is obsessed with it!! haha but she's funny aswell and we have interesting lessons, so much fun really :wink:

but yeah everyone says she's the best teacher!! and i'm really gonna miss those lessons.. :frown:

but anyway, i think i know a fair bit about the course as we have a girl in the class who asks every conceivable question!!! but anyway! my score on the practicals was 83/90. should have been 84, but i didnt give in the piece of paper with the titres on so lost a mark!
but i'm gonna fail the special study (food science) because its so boring!!

Reply 34

firestone

9

man_in_black

I use the same wording too. I don't like to miss out words just in case one or two of them are really important. I'm hoping it's alright to do that. Are there any websites that give advice on the summary? Revision guides don't mention it....

I’ve missed out half the reactions, that probably explains why lol.

Really hoping that it’s okay to use the same wording – it’ll take too much mental energy after two hours of exams for me to have to figure out what they’re saying. No idea about the summary – there isn’t that much they could say about it I guess.

I know! Topic 6…I think that’s the hardest topic in terms of the most to remember. I didn’t really look at the limonene and extraction of iodine reactions, missed out 6.6 and 6.7, and ignored most of 6.8 – I thought that they weren’t that important. Maybe I should look at them at some point before the exam…are we seriously expected to remember all those equations of the sodium chlorate(I) and potassium halates(V) – they’re so specific!

Gregorian IV

I'm pretty surprised that some people are doing Unit 1...or are you resitting them?

No it’s the first time I’m taking Unit 1. It’s because at my school we’re doing all the units in the summer for most subjects. Lucky – you’ve got Unit 1 out of the way! Unit 2 – I can hardly understand Section B…

*Emily*

you dont need to know the content for AS for the background readings

Phew, at least there’s no need to worry about it yet. Thanks :biggrin:

*Emily*

my chemistry teacher is amazing!!

*Emily*

but i'm gonna fail the special study (food science) because its so boring!!

Don’t know much about the special study, but I’m sure you’ll be fine :smile:

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Edit:

Looking at the specification from the Edexcel site which says, (Page 28)

"Content 6.6 and 6.7 are in the Student's Book but will not be examined as part of this specification."

Students may be asked to:
...evaluate information by extraction from text and the Book of Data about the sources of the halogens, and their role in human metabolism (examined in the synoptic paper only)."

Question about the second part - does "examined in the synoptic paper only" just refer to the roles of halogens in human metabolism or the sources of halogens too? Hopefully...