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

I said the other way round?

What did people get for the mass of compound A?

What did people get for the mass of compound A?

I believe it was 135

you could be right im not sure, i just remember reading somewhere that organisms will only produce one optical isomer and it doesnt state in the question whether chemical synthesis involves chiral pool synthesis or an enzyme catalyst so i presumed the reaction had no measures to ensure one of the optical isomers, so you get me?

guys i got this as my fragment for m/z = 44
surely its right, right?

2.66 is the correct answer.

This is making me so depressed rn, just realising I've dropped 9marks already...

You're right -I've just looked at the specification:
"using natural chiral molecules, such as Laminoacids or sugars, as startingmaterials."

question about stitches: is it asking about hydrolysis of photodegradable. or you need both to score 3.

At a guess, anything in the range 58-60.

How about...

90/90 - 58
A* - 54
A - 50
B - 46
C - 42
D - 38
E - 34

ah same Its gonna suck if the boundaries are A=52

Dissolvable stitches are used for internal and external stiches. If they're used inside the body they are hydrolysed. For external stiches, the part inside the body gets dissolved but the bit outside has to be removed by a dr as it doesn't break down. PLA is used in plastic cups etc so over the time period they were talking about (a few weeks), common sense says they don't photodegrade.

guys i got this as my fragment for m/z = 44
surely its right, right?

ah same Its gonna suck if the boundaries are A=52

anyone?

maybe so, but according to the text book and ocr, the link we're supposed to make is cis are naturally occuring and trans are produced via processes like making margerine

Read over the textbook, read chemguide, keep at it until you get it.

270/300 (90% average) across A2 units and 80% average across all A2 and AS units

You may find this useful http://www.ocr.org.uk/i-want-to/convert-raw-marks-to-ums/

your carbon furthest to the left has two bonds removed, not one. Your structure would have a 2+ charge. Sorry man I don't think it's right

Dissolvable stitches are used for internal and external stiches. If they're used inside the body they are hydrolysed. For external stiches, the part inside the body gets dissolved but the bit outside has to be removed by a dr as it doesn't break down. PLA is used in plastic cups etc so over the time period they were talking about (a few weeks), common sense says they don't photodegrade.