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UNOFFICIAL MARKSCHEME ocr chemistry gateway today

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Reply 20
Avatar for Irf00
Irf00
2
Original post by mxskaan
I swear there wasn't an atom economy question?

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No I don't think there was. I remember percentage yield tho. They're similar
Original post by Irf00
No I don't think there was. I remember percentage yield tho. They're similar


what did you get for the % yield q
i got somewhere in 70s i can't remember
Reply 22
Avatar for Irf00
Irf00
2
Original post by mxskaan
what did you get for the % yield q
i got somewhere in 70s i can't remember


Yeah defo somewhere in the mid 70s
Original post by robyn2000
I put that larger molecules dont evaporate as easily, stronger intermolecular forces? But not too sure


I didn't even think about molecule size, damn...

I went with yes, it would be okay, because its melting point was very low and its boiling point very high so would be a liquid at room temp (25 degrees C), which was one of the criteria.
Also I didn't know what to do for the incomplete combustion q I put carbon monoxide as well as carbon

I got 2CH4 + 2.5O2 --> CO + C + 4H2O

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Reply 25
Avatar for samg2
samg2
4
for the conservation of mass question you just had to prove that the product had the same relative atomic mass as the subtance being decomposed right??? 168 and 168, therefore conservation of mass?

and for the addition polymerisation question DID YOU HAVE TO include the n??? ive heard that was just an add on or is it required???
Original post by samg2
for the conservation of mass question you just had to prove that the product had the same relative atomic mass as the subtance being decomposed right??? 168 and 168, therefore conservation of mass?

and for the addition polymerisation question DID YOU HAVE TO include the n??? ive heard that was just an add on or is it required???


in previous questions on past papers it was worth a mark so i reckon it was needed
Reply 27
Avatar for samg2
samg2
4
Original post by brainzistheword
in previous questions on past papers it was worth a mark so i reckon it was needed


http://www.ocr.org.uk/Images/176611-mark-scheme-unit-b741-02-modules-c1-c2-c3-higher-tier-june.pdf
Go to page 7 ^^

the answer does include the n but in the allow section there is no n or brackets lol

dammit i knew i should've just wrote 'n', its literally the easiest letter to write!!!!
Original post by samg2
http://www.ocr.org.uk/Images/176611-mark-scheme-unit-b741-02-modules-c1-c2-c3-higher-tier-june.pdf
Go to page 7 ^^

the answer does include the n but in the allow section there is no n or brackets lol

dammit i knew i should've just wrote 'n', its literally the easiest letter to write!!!!


The reason that doesn't have an n is because it shows monomers joined together - basically the chain which they allow, but if you are showing the poly(hydrocarbon) with brackets then you need the n
:smile:

It's only a mark so don't feel bad about it :smile:

How did you find the exam overall and what did your school think of it? :smile:
Original post by rose.i
I got E for the first question and F and C for the second one. And then C18 H8 for the third one I thinkk


SAME!!!
Reply 30
Avatar for nahyr
nahyr
2
For question 3 with the graphs and stuff I think it would be pie chart and bar graph
Reply 31
Avatar for nahyr
nahyr
2
Original post by U-GradeStudent
SAME!!!


I got E I think it was the molecule with a double bond and only carbon and hydrogen atoms i hope. Also it was C8H18
Original post by mxskaan
Also I didn't know what to do for the incomplete combustion q I put carbon monoxide as well as carbon

I got 2CH4 + 2.5O2 --> CO + C + 4H2O

Posted from TSR Mobile


Same!! I was gonna put carbon monoxide but it only said carbon was produced. I also put watered there needed to be someone with a h in!
What were the answers for the first two questions in C3.... 8000 and 10? Or is that what you put? Thanks xx
Original post by nahyr
I got E I think it was the molecule with a double bond and only carbon and hydrogen atoms i hope. Also it was C8H18


I'm pretty sure it was! xx
Reply 35
Avatar for nahyr
nahyr
2
Original post by U-GradeStudent
What were the answers for the first two questions in C3.... 8000 and 10? Or is that what you put? Thanks xx


I'm pretty sure for that question the first one was 32000J and then the next one was 76.2 degrees
Original post by nahyr
I'm pretty sure for that question the first one was 32000J and then the next one was 76.2 degrees


Phew!! That's what I got!! :biggrin:
Original post by ellamoon_22
I'm not sure what they asked for if they asked for energy supplies it would be 32000 if they asked energy per gram it would be 8000


Nearly 100% sure they asked about finding energy released from 2g..
What did people put for the question on bar/line/pie/scatter graphs?
first is pie
second is line

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