The Student Room Group

OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD

Scroll to see replies

Original post by lai812matthew
if that is the case then HCl would have been accepted also without writing diluted. they just don't allow concentrated HCl.


How many marks was this question for the flowchart only? Was it 1 mark for conditions and 1 for reagents?
Original post by jadder1224
1465939797921-1945820337.jpg is this octa deca 12 enoic acid ?


That's what I drew anyways >.<
Original post by jadder1224
1465939797921-1945820337.jpg is this octa deca 12 enoic acid ?


That's an 18 carbon skeletal carbon chain? It was C17
Original post by NervousBoy
That's an 18 carbon skeletal carbon chain? It was C17


But there was the C from tbe COOH as well so 18 altogether?
Original post by Rafia Mafia
could you post the 2015 links here i cant seem to find them :/



Chemhume have uploaded the 2015 papers
Is there gonna be a poll for people to vote on difficulty or nah?
1465940309142-1981315228.jpgfor the triglyceride would this be okay? Cant remeber the number of hydrogen atoms
Original post by NervousBoy
How many marks was this question for the flowchart only? Was it 1 mark for conditions and 1 for reagents?

4marks in total for that.

Original post by coolgamer
How many marks for a B grade ? Do u think

Gonna predict mid-40s.

Original post by jadder1224
1465940309142-1981315228.jpgfor the triglyceride would this be okay? Cant remeber the number of hydrogen atoms

Yes that should be fine I did (CH2)16-CH3
For the repeat unit of polylactic acid did it just ask for one repeat unit ?
What was J in the very last question?


Posted from TSR Mobile
Guys, for the hydrolysis of the polyamide, it didn't say whether it was in acidic or alkali solution right? it just said monomers?

the only one with the acid hydrolysis was the HCL one right?
It didn't say whether they were trans or not though? So surely from not knowing wether they were trans or cis...the answer will be the saturated fats?
1465941256100-649166194.jpgdoes this look familiar ?
Original post by Cal 1
For the first question it was the THIRD fatty acid. The question asked which is 'most LIKELY' to cause heart disease. The third fatty acid is most LIKELY to have at least one trans bond, and therefore most likely to be a trans fatty acid. It is TRANS FATTY ACIDS that act like SATURATED FATS. Key point to note here is there is a difference between TRANS FATS and TRANS FATTY ACIDS.

Now, in my personal opinion, you've over-complicated this massively. The first question on any paper is usually intended as an easy opener that every candidate can score well on. Stearic acid is likely cause heart disease and obesity because it is saturated (or SATURATED, as you might put it). Because of the lack of a C=C bond in there, it means that the acid (which is a straight chain, remember) can stack and result in a build up of plaque in the arteries. In the case of the third acid, if anything it's least likely to form plaque because there are two double bonds and these can give rise to multiple orientations!
Can anyone remember what mass they got for the yield question?
Original post by Jackiee98
Can anyone remember what mass they got for the yield question?


2.66


Posted from TSR Mobile
I also thought it was odd they even asked a question about fats and health given the recent breakthroughs that says fats probably don't cause increased risk of CHD...did anyone else find that really untopical given that loads of scientists now disagree/ we don't really know whats fats do
Original post by drandy76


Same!
Original post by lai812matthew
only when the stitches are photodegradable they turn into carbon dioxide and water which they aren't.


I'll refer you to the textbook again. Page 60 "A biodegradable polymer is a polymer that breaks down completely into carbon dioxide and water" and again on page 55 "Poly(lactic acid) is biodegradable"
I struggle to see your argument?
Original post by VMD100
I'll refer you to the textbook again. Page 60 "A biodegradable polymer is a polymer that breaks down completely into carbon dioxide and water" and again on page 55 "Poly(lactic acid) is biodegradable"
I struggle to see your argument?


my mistake sorry`

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you