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OCR B F332 Friday May 27th 2011 exam discussion

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Reply 20

adam*

Original post by lily92

Anyone got a list of reagents and conditions?

This is where I'm losing marks on past papers, I really need to learn this. A list would be great!

Reply 21

Hanz_a93

Original post by lily92

Anyone got a list of reagents and conditions?

Alkenes to alkanes=
React with hydrogen
platinum catalyst at rtp

Alkenes to alcohols=
hydrated by steam
Phospheric acid catalyst
300 degrees c
60 atm

Alcohols to alkenes=
Reflux alcohol
excess concentrated sulfric acid
170 degrees c

Alcohols:

Primary to aldehyde=
potassium dichromate
sulfric acid
heated & distilled

Primary to carboxylic=
Excess sulfric acid
potassium dichromate
heated under reflux

Goodluck with the exam!

Reply 22

kishenp

Original post by Hanz_a93

This is amazing !!
Is this all we need to know for the reagents and conditions ?
Thanks alot

Reply 23

CullenLoverX

How did everyone find it? First question was a bitch tbh but after that it seemed to be OK... Advance Notice questions were brilliant, I loved them :smile:

But one thing I'm so annoyed about is when I drew the repeating units, I didn't put a line coming out to the side of each C atom (for it to link to another monomer) will I still get the mark?

What was the answer to the question where they gave those 3 equations of ozone and asked you to write the overall equation?
and what are the answers to the questions on the formula of calcium (ClO) and the question after that, something about the element being both oxidised and reduced?

This paper was quite hard IMO so what do you think the grade boundaries will be like? I'm thinking 73-74 for an A or is that too low?

Reply 24

Failed123

Original post by CullenLoverX

How did everyone find it? First question was a bitch tbh but after that it seemed to be OK... Advance Notice questions were brilliant, I loved them :smile:

Hmm well I thought it was an okay paper, though saying that I could still come out with something lame like a D or something instead of a B / A haha. Well I like to know if other people thought this was hard or easy. Get a general feel or what others thought in terms of difficulty. Though this is TSR so I imagine that even if all the questions were related to content not even on the bloody specification you lot will still claim it was the easiest exam ever :mad:

Reply 25

CullenLoverX

Original post by Failed123

Lool you're right there :tongue:

But most people I've spoken to found it relatively difficult...

Reply 26

Joey17

I thought it went well actually. Yeah I thought the first question was quite hard and that summarising of the three NO equations. Also is CO a triple bond?

Reply 27

croag

Didn't like the halogenoalkane one with ozone depletion, and I got the ca(clo3)2 one wrong, but it was OK. For a repeating unit can you add in n and the brackets??

Reply 28

Caleb_141

When I first opened the paper the first questions really knocked me, I think they pretty much knocked my confidence right through the entire paper until I got to the end. By the time I'd answered all the easy questions I still had an hour to go so I began going back through them all.

There were a few which I know I got wrong (the atom economy one and the carbon monoxide dot cross) as I just didn't think that they would come up. Other than that though I felt pretty confident with the rest of the questions.

With chemistry though its always hard to tell how well you did imo :P haha

Reply 29

ingridnicacio

I thought it was dead hard, especially compared to jan 11 which was really straigh forward questions :frown:

I didnt even finish the paper, so probably got around 50/100 ...

most people in my class found it easy cuase everyone s got a tutor so... ¬¬

Reply 30

Joey17

Original post by croag

Didn't like the halogenoalkane one with ozone depletion, and I got the ca(clo3)2 one wrong, but it was OK. For a repeating unit can you add in n and the brackets??

You'll be fine with the brackets and n :smile:

Reply 31

Caleb_141

Original post by Joey17

I thought it went well actually. Yeah I thought the first question was quite hard and that summarising of the three NO equations. Also is CO a triple bond?

Carbon monoxide looks like this:

http://sixthsense.osfc.ac.uk/chemistry/bonding/answer/checkpoin5_co.htm

I got it wrong, I just left it as a dative covalent bond (might still get a mark for that though...maybe)

Reply 32

the_flying_walrus

I also thought the paper was quite tricky. It was doable, but there were a lot of weird questions, and then they bought in some stuff from the first unit as well, like shapes and bond angles. Luckily I could remember it :smile:

Reply 33

parallal

This exam was so hard ):
As soon as I read the first question I knew that there was no way I'm getting an A on this.

Reply 34

Trixy.Sam

anyone have an unofficial mark scheme yet??

Reply 35

TimWestwood

Hated this paper; I swear we didn't cover a lot of the reactions that they asked you for the reagents and conditions on...

(edited 12 years ago)

Reply 36

ingridnicacio

I am so relieved people here found the exam hard because the hopefully they lower the boundaries realllly low :smile:

Reply 37

stealth_writer

Original post by the_flying_walrus

i also thought the paper was quite tricky. It was doable, but there were a lot of weird questions, and then they bought in some stuff from the first unit as well, like shapes and bond angles. Luckily i could remember it :smile:

shapes and bond angles??????????????????????????????????????????????????????

Reply 38

parallal

For the 7 mark ozone question I put:
UV radiation from the sun is absorbed by the ozone. This is helpful because UV radiation has a high energy and freqeuncy and can be harmful to humans because it causes skin cancer. Ozone is formed when oxygen in the atmposhere absorbs UV radiation and splits homolytically into two oxygen radicals. The oxygen radicals then react with oxygen to form ozone.

Then I put this equation:

O2 + O --> O3

Think this will give me the full 7 marks? :confused: