OCR AS - Chemistry Unit F322 - Chains, energy and resource - REVISION!

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Reply 60

SteveCrain

Original post by Contrad!ction.

Ah, anyway, topicwise: Give 5 principles of Green Chemistry

Hey; which 5 do we have to know. In the text book there are 12, and I cba learning them if we only need to know 5...?

Reply 61

Contrad!ction.

Original post by SteveCrain

Hey; which 5 do we have to know. In the text book there are 12, and I cba learning them if we only need to know 5...?

I don't think there's a set number, I just made the q up. I'm trying to focus on my maths and have only done the hydrocarbons bit. I'd try to remember as many as possible because there might be a large q on them. I'd consult the syllabus for that one, I haven't had a teacher for the resources section so I'm not the best person to ask.

Reply 62

SteveCrain

Guys can someone upload the exam style answers on the cd from the textbook?!?!??!

Reply 63

Muggle#334025

Original post by SteveCrain

Guys can someone upload the exam style answers on the cd from the textbook?!?!??!

Are those the ones you were looking for?? :smile:

Guys does anyone know how much detail we need to know the polymer waste stuff in, do we need to know all the identification codes. I cant seem to learn this stuff its too boring :sleep:

exam style answers.pdf249.6KB

Reply 64

YingYang

*subscribes*

not ready for this exam, probably had the least prep for it so far.

Reply 65

SteveCrain

What are the conditions and what is the catalyst used in the Haber Process?

(whoever answers asks another question)

Reply 66

student777

Original post by SteveCrain

What are the conditions and what is the catalyst used in the Haber Process?

(whoever answers asks another question)

High pressure, low temperature (350 degrees ish) Iron catalyst

How does fractional distillation work?

Reply 67

SteveCrain

Original post by student777

High pressure, low temperature (350 degrees ish) Iron catalyst

How does fractional distillation work?

(Crude oil is vaporized and passed into a fractioning column) where it is separated on the basis on the different boiling points of the components in the oil.

Outline the "ozone" cycle- formation, absorption of radiation and overall equation.

Reply 68

thenameisdj

Original post by J DOT A

Tip for you guys that are taking this exam... you have to do as many application questions as possible. Trust me, the past papers of the old spec does not gear you up for the real exam.

Thanks for the tip! I was wondering what are application questions and where can I find them?

Reply 69

Bright

:/ I feel so behind with revision when I see things like this.. I haven't done a single past paper apart from mock.. but when it was unit 1 I used to get near to full marks at the start of xmas holiday without even revising the topic.. :frown:

(

Reply 70

Joseppea

Original post by Bright

(

I feel the same about this topic. :frown:

There's so much our teacher hasn't actually taught us and most of it is going way over my head - and it doesn't usually in any other subject :confused:

Just gonna have to memorise some past paper answers as our teacher always tells us the wrong ones anyway :rolleyes:

Reply 71

J DOT A

Original post by Joseppea

I feel the same about this topic. :frown:

There's so much our teacher hasn't actually taught us and most of it is going way over my head - and it doesn't usually in any other subject :confused:

Just gonna have to memorise some past paper answers as our teacher always tells us the wrong ones anyway :rolleyes:

The good thing about this exam is that you dont really need to remeberise anything, just UNDERSTAND everything.
The organic is standard, just MAKE SURE you check if they ask if you want structral or displayed formula, and for the love of god dont forget to put H20 after you add an alcohol + [O].
It may seem like you wont now, but the pressure of the exam ect, you make stupid mistakes.... so keep your head about you!

Reply 72

Joseppea

Original post by J DOT A

Thanks

I'm hoping it'll all pan out alright - I pwned the practicals and got an A in the first exam, so I only need a B in this one to get an A overall :confused:

- I don't know how I managed that but I'm not complaining :tongue:

+1 when I'm recharged XD

Reply 73

Bright

Original post by Joseppea

I feel the same about this topic. :frown:

There's so much our teacher hasn't actually taught us and most of it is going way over my head - and it doesn't usually in any other subject :confused:

Just gonna have to memorise some past paper answers as our teacher always tells us the wrong ones anyway :rolleyes:

Haha, I just did some green chemistry..

I think the exam will have much more organic chemistry than energy etc so gotta start revising that now.. -__-
I hope we get A's! ^___^

Reply 74

Bright

Original post by J DOT A

That's not a good thing.. it's all about memorising! lool :P

Reply 75

SteveCrain

Can someone explain why there are 8 electrons in an O radical?

Reply 76

Bright

Original post by SteveCrain

Can someone explain why there are 8 electrons in an O radical?

http://www.thestudentroom.co.uk/showthread.php?t=1296921

If you understand what they are talking about please explain to me aswell.. all I got was Oxygen has 2 unpaired electrons (di radical)
.. :/

Reply 77

student777

Original post by Bright

http://www.thestudentroom.co.uk/showthread.php?t=1296921

If you understand what they are talking about please explain to me aswell.. all I got was Oxygen has 2 unpaired electrons (di radical)
.. :/

Ok... I think I get this.

An oxygen atom O has 2 unpaired electrons. You might think that makes a pair, but those electrons occupy different p orbitals. This makes oxygen a diradical.

A molecule of oxygen O2 has 2 oxygens in a double bond, O=O. The four unpaired electrons are shared in 2 covalent bonds. When these bonds break by homolytic fission, both bonds are broken and the unpaired electrons returned to the oxygen atoms.

So an oxygen radical is in fact just an oxygen atom, O. Therefore it has 8 electrons :smile:

(edited 13 years ago)

Reply 78

Bright