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Official OCR AS Chemistry 4th June Discussion/Prediction thread

WHO'S TAKING THESE EXAMS?? I’m taking foundation chemistry, how far how fast and chains & rings soon what’s likely to come up in the exam, my teacher said it’s unlikely for them to ask much about: intermolecular forces for foundation
rates of hydrolysis for chains & rings. What do u guys think?:how u preparing for the exams?

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Reply 1

Esma

Intermolecular forces ALWAYS comes up :| Im pretty sure of that,no?

Reply 2

DanielWhit

Bound to get the old enthalpy change questions for How far, How fast?, always do.

Learn all the definitions and thats a good few marks in the bag straight off.

EDIT - I am now a "Respected Member" - first step to world domination!!

Reply 3

thebluestjade

humminteresting

Hey people I’m taking foundation chemistry, how far how fast and chains & rings soon what’s likely to come up in the exam, my teacher said it’s unlikely for them to ask much about: intermolecular forces for foundation
rates of hydrolysis for chains & rings. What do u guys think? :biggrin:

For chains and rings, I find there are usually 2 functioncal group comes up this year, so it'll be a gd idea to check what came up in Jan 08 paper coz it's unlikely to come up again.
However, u know these groups are somehow related to each other though, the point is to focus more on what didnot come up. Dont u think that there are too much reactions for this module though?

Reply 4

Jordan_U

hydrolysis can come up... it could and i KNOW intermolecular forces will be there and How far how fast is quite repetitive ubless they change it

Reply 5

maria737

i'm thinking mass spectrometry might but to be honest i have no idea really. i'm so worried about chemistry, i've only done like 1 days worth of revision, if that and the day before i have bio and then history before that. i soooooooo wanted an A but i know it's not gonna happen now. :frown:

Reply 6

humminteresting

what essay question do u think might come up

Reply 7

Jordan_U

I have a feeling Mass Spectrometry will come up my prediction

Reply 8

humminteresting

i think your right it hasn't come up for a long time

Reply 9

Rich19

I haven't seen Mass Spectrometry in many of the past papers I've done (although that isn't too many!), but I'm hesitant to make any predictions as to what may/may not come up. I got a fairly big shock in my physics exam when a couple of totally unexpected "big" questions came up - seems they (OCR) broke the mould a little with that. Perhaps they'll do the same in chem.

Reply 10

humminteresting

with chemistry its easy to predict what essay question they might ask as there is only a limited number they can ask.

Reply 11

sweetlikesugar

can someone please explain the rate or hydrolysis for haloalkanes to me? I dont get it.

Is it
C-Cl>C-Br>C-I for bong strength

But then the rate of hydrolysis is faster for
C-Br> C-Cl

Reply 12

humminteresting

lool are we the only ocr ppl taking these exams

Reply 13

humminteresting

sweetlikesugar

can someone please explain the rate or hydrolysis for haloalkanes to me? I dont get it.

Is it
C-Cl>C-Br>C-I for bong strength

But then the rate of hydrolysis is faster for
C-Br> C-Cl

Rate of hydrolysis I > Br > Cl > F because
Order of bond strength C-F > C-Cl > C-Br > C-I
Shown by adding AgNO3(aq) and timing how long silver halide precipitate takes to form

The Group 7 elements gain an electron when they react. Down the group the outer electron is further from nucleus and more shielded so gained less easily
This is equivalent to saying that oxidising power decreases down the group (oxidising power, or strength as an oxidising agent, is the ability to remove an electron from another species)

Reply 14

Esma

humminteresting

lool are we the only ocr ppl taking these exams

*puts hand up* I'm taking units 2 and 3 too!
Gosh,all them reactions for unit two.. :eek:

..Just do lots of papers and hopefully,we will all be fine :smile:

Reply 15

dani2511

Esma

*puts hand up* I'm taking units 2 and 3 too!
Gosh,all them reactions for unit two.. :eek:

..Just do lots of papers and hopefully,we will all be fine :smile:

Wait till you get to Chains, Rings and Spec...
there are quite a few more reactions to learn for that lol.

Reply 16

Esma

dani2511

Wait till you get to Chains, Rings and Spec...
there are quite a few more reactions to learn for that lol.

Oh well

Lool..Bring it on? :s-smilie:

I'll climb that mountain when it comes hopefully :redface:

Reply 17

CCJ

I don't like to guess whats gonna come up in an exam .. just learn all you can about everything and hope for the best! I have noticed, they have some tricky questions in the past papers, mainly the one markers that try to catch you out. I've done one set of past papers from 01-07, half way through my second set of papers, and it just comes down to knowing your stuff and exam technique.

Usually they test you out (especially for Chains & Rings), to see if you've learned the book equations or if you really understand it, they do this by changing the R group to something ridiculous ... one paper stands out, and it was something like reactions of Menthol? C10H19OH, and its skeletal was very weird, but its just applying what you know.

Also for the essay questions ... STATE THE FREAKIN' OBVIOUS! :P, learned the hard way that overcomplicating things will cost you.

Reply 18

Esma

Need to learn reforming and cracking and isomerisationn :mad:

Its so boring but they could ask it as an essay,so I don't want to screw it up

Reply 19

CCJ

for those kinda questions they'll only ask you, whats it for? hows does it help and show an equation :P ... infact all of them you can get away with sayin produce more efficient fuels/petrol additives/polymers (cracking)