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OCR Salters Chemistry B F332 Advance Notice May 2011 Polymers on the move

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It's basically the actual mechanism for addition polymerisation (it's how they add together). I think it's in the syllabus as it's in some of my guides but if it isn't, it could quite possibly be useful for the advanced notice question. I quote from the advanced notice:

"These are polymerised by a free radicalinitiated polyaddition." - from the Bonding polyalkenes section.

So they could very possibly ask you about the mechanism I explained.

No problem :smile:

. If there are any other mini-topics you would like explaining just shout. And what baffoon neg'd you? :angry:

Yeah, thanks, I'm scribbling some notes down on it now... ready for cramming in the morning! (it works for me, before people tell me not to cram! :colondollar:

)
Looking at it it seems faaaairly self-explanitory (if you know how radicals work anyway) and there's a bit about it on the advance notice so... it shouldn't be too much of a problem! :biggrin:

Reply 121

icedragon

Original post by Toshiya

Yeah, thanks, I'm scribbling some notes down on it now... ready for cramming in the morning! (it works for me, before people tell me not to cram! :colondollar:

)
Looking at it it seems faaaairly self-explanitory (if you know how radicals work anyway) and there's a bit about it on the advance notice so... it shouldn't be too much of a problem! :biggrin:

Yep. I have a 2 hour exam in the morning so not much cramming for me :frown:

. Will just have to rely on my existing knowledge to pull out 100ums (or not... :tongue:

Reply 122

Bi0logical

I've got an exam in the morning as well :/ but just some quick cramming notes :smile:

First ionisation enthalpy is the energy needed to remove an electron from one of of isolated gaseous atoms of an element.

Group 0 elements have a high ionisation enthalpy, this is because it is difficult to remove an electron from these atoms with full outer shells, also they are very unreactive.
First ionisation enthalpy increases as the atomic number increases, so as you go across the period the first ionisation enthalpy will increase. The nuclear charge increases going across the period from left to right and the electrons are being added to the same shell. This means that there is a greater attraction between the nucleus and the electron, therefore more energy is needed to remove the electron

First ionisation enthalpy DECREASES as you go DOWN a group, this is because the attraction between the nucleus and the outermost electrons decreases. There are more filed shells of electrons between the nucleus and the outermost electron.
The outermost electron is further from the nucleus
The filled electron shells shield the positively charged nucleus from the outermost electrons.

Examples of ionisation enthalpies;

Cl(g) --> Cl+(g) + e- (first)
Cl+(g) --> Cl2+ + e-

There is a big jump in ionisation enthalpies when an electron is removed from a full electron shell;
e.g. in aluminium the electron arrangement is 2.8.3 - so when the 4th electron is removed it will require much more energy compared to the 2nd or 3rd.

Reply 123

master_blaster66

good luck to everyone for this exam...one of the hardest exam in this course

Reply 124

CloClo7

Can someone please list the reaction conditions...I can't access the Spec!!

I know the oxidation of alcohol (heat under reflux with excess acidified potassium dichromate right??) but thats all I can remember.

Reply 125

Doughnut

Does anyone have the F332 June 2010 mark scheme. OCR's website decides to be down on the day of the exam!

Reply 126

croag

My revision plan yesterday failed so I'm going into this exam with nothing but my memory of over 3 months ago. Some of the questions are usually very easy, but when it asks you to name reagents etc. I always get stumped. Usually drying agents would be Sodium Sulphate, or Silica Crystals. Oxidising agents are things such as Potassium Dichromate (this often comes up).

Ozone depletion comes up a lot as big questions, usually easy marks. The maths questions are easy marks - but any time it asks me to talk about carbonyl or anything to do with polymers I'm stumped.

Reply 127

Bi0logical

Original post by CloClo7

Halogenoalkane to Amine group: The Halogenoalkane is heated with concentrated ammonia solution in a sealed tube R-Hal + NH3 --> R-NH2 + HAL- + H+

Halogenoalkane to Alcohol: Hydrolysis reaction by heating under refux
R-Hal + H20 ---> R-OH + H+ + Hal-
OR Heat under reflux with NaOH (AQ) with ethanol as a solvent
R-Hal + OH- --> R-OH + Hal-

Alkene to Alcohol: Electrophilic addition with water; Phosphoric acid/silica at 300 degrees Celsius at 60 Atm OR with conc H2S04, then H20 at 1 ATM

Alkene to Alkane; Electrophilic addition, where H2 is the electrophile. Pt Catalyst Room Temperature and Pressure OR Ni Catalyst at 150degrees celcius and 5 atm

Alkene to Halogenoalkane; electrophilic addition with Hbr (AQ) @ room temperature and pressure

Alkene to Bromoalcohol: electrophilic addition with Br2 (AQ)@ room temperature and pressure

Alcohol to Ketone: Excess ACIDIFIED Potassium Dichromate, heat under reflux (SECONDARY alcohol)

Alcohol to Carboxylic acid: Heat under reflux to carry oxidation through to carboxylic acid (PRIMARY alcohol). with EXCESS ACIDIFIED Potassium Dichromate

Alcohol to Aldehyde: Heat under reflux with acidified potassium dichromate, distill of once made to prevent further oxidation through to carboxylic acid.

COLOUR CHANGE OF ALL ALCOHOL OXIDATION; ORANGE TO GREEN

Alcohol to Alkene; Elimination/Dehydration reaction, Alumina (Al203) catalyst, 300degrees celcius, 1 atm. (H20 is the product)

Alcohol to Halogenoalkane;
This is done by reacting 2-Methyl Propan2ol with HCL at room temperature to form 2-chloro-2methyl propane (reaction carried out in a SEPERATING FUNNEL)

Alkane to Halogenoalkane; radical substitution reaction
requires gas phase and high temperatures or presence of UV radiation, e.g. in Stratosphere

example;
Cl2 --> Cl" + Cl" (Photodissociation, "=radical)
Cl" + CH4 --> CH3" + HCL
CH3" + CL" --->CH3CL

Reply 128

jakeisthebest

I found the paper quite hard compared to past papers :/

Does anyone know what would get full marks on the 7 mark question?
Also, what is a use for chlorine other than water treatment?

Reply 129

minip12qss

chlorine can be used for bleach but i don't know about the 7 mark one. What did you put for the sub shell question

Reply 130

parallal

Original post by jakeisthebest

I found the paper quite hard compared to past papers :/

Does anyone know what would get full marks on the 7 mark question?
Also, what is a use for chlorine other than water treatment?

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
Not sure if that's the full 7 marks though...

As for chlorine I put it is used as a disinfectant in cleaning supplies.

Reply 131

golddust&lipgloss

Original post by minip12qss

chlorine can be used for bleach but i don't know about the 7 mark one. What did you put for the sub shell question

5p6. i hope that's correct :frown:

(edited 12 years ago)

Reply 132

golddust&lipgloss

Original post by jakeisthebest

I found the paper quite hard compared to past papers :/

Does anyone know what would get full marks on the 7 mark question?
Also, what is a use for chlorine other than water treatment?

i put medicine manufacturing :/. couldn't think of anything else, it probably is wrong. hmph.

Reply 133

Hanz_a93

Original post by jakeisthebest

I found the paper quite hard compared to past papers :/

Does anyone know what would get full marks on the 7 mark question?
Also, what is a use for chlorine other than water treatment?

CFC's

Reply 134

Hanz_a93

We all owe hudzy BIG TIME :biggrin:

Reply 135

matt1107

Did you mean the question about the importance of ozone in the stratosphere?

Reply 136

matt1107

would i get a mark for chlorine being used in CFC'S?

Reply 137

kinkin

who ever posted stuff on extract i love you dude!!!! only part i didn't get was another way co2 produced i said burning hydrocarbons LOL

Reply 138

hash007

Original post by golddust&lipgloss

5p6. i hope that's correct :frown:

Wasnt it just drawing the Iodine with a full shell, one extra elctron so it had a negative charge?

Anyway I found that paper really hard! The first page just bamboozled me, I thought it got better as it went on though. The last section was pretty easy, about the article.
Was does it mean if it's (I) next to the molecule, I said the chlorine had a 1+ charge.

Reply 139

hash007

Original post by kinkin

who ever posted stuff on extract i love you dude!!!! only part i didn't get was another way co2 produced i said burning hydrocarbons LOL

Which question was that? About the carbon dioxide?

Also the one where you had to name the functional groups just confused me so much! It was alcahol and Alkyne you had to put I think, I put down ester and aldehyde :l