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OCR Chemistry A Exam Thread (Breadth - May 27 2016 and Depth - June 10 2016)

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Original post by TH3-FL45H
For the last question I put butanoic acid instead of 2 methyl propanoic acid :facepalm: Figured it out 30 seconds after the exam finished ffs

How many marks will I lose? 2? 3?

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My teacher said that you'd only lose like 1 mark for that 2 marks at the most. I think
Guys got the phosphorus and chlorine molecules, is it cause phosphorus has stronger induced dipole dipole cause more electrons ect?
I wrote : 1st line: NO(radical) +O3 -> 03(radical) + NO
2nd line: O3(radical)+N2 -> NO(radical) + O2
So O3(ozone) is lost (not sure if 100% right)
Original post by Awsomedude
what did people write for the ozone depletion propagation steps?
Reply 1003
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11234
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Original post by 4nonymous
Yh was thinking the same

What about 67 to 2sf
Original post by LordStark
I'm pretty sure it was. All the peaks (including 43) work fine with butanoic acid. I thought the mention of a secondary carbocation was just useless information - there isn't carbocations present in carboxylic acids anyway, only during reaction mechanisms right?


Thanks :smile:

They could useful though cause the carbocation can talk about the fragments


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Original post by 2kk2
in the enthalpy profile diagram did it say not to label the activation energy?

Yep ,
Original post by TH3-FL45H
For the last question I put butanoic acid instead of 2 methyl propanoic acid :facepalm: Figured it out 30 seconds after the exam finished ffs

How many marks will I lose? 2? 3?

Posted from TSR Mobile


Given that you have used the evidence appropriately you should lose just one.
Original post by HaveFa1th
No + o3 --> no2 o2
no2 + o --> no + o2

YESSS
Original post by Michal-sweaty-g
I wrote : 1st line: NO(radical) +O3 -> 03(radical) + NO
2nd line: O3(radical)+N2 -> NO(radical) + O2
So O3(ozone) is lost (not sure if 100% right)


Nah, this isn't right sorry:frown: it's no• +03 goes to n02• +02........NO2•+O goes to no• + 02
Original post by 4nonymous
Liked that exam :smile:
Here's what I remember
Pa=4.46*10^6
rate at 200 seconds was 0.0022
1.85g for the mass of something (srco3?)
percentage yield 67.4%
metal was calcium
z-pent-2-ene (compound A)
last question compound C was butanoic acid?
The major product was the one where Br went on the 2nd carbon (6 marker curly arrow method)


i got butanoic acid for last one, but apparently it was a branced structure :/ cause it said something about secondary carbocation causing the biggest peak in the ms.
Original post by ineedA
Guys got the phosphorus and chlorine molecules, is it cause phosphorus has stronger induced dipole dipole cause more electrons ect?

Can someone please answr this
Original post by ineedA
Can someone please answr this


... I talked about Van Deer Waals and said Phosporus' molecule is heavier and have more electrons


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what did everyone write for would the gas produced increase decrease or stay the same for the first few questions
Original post by 2kk2
in the enthalpy profile diagram did it say not to label the activation energy?


It said you are not EXPECTED to know the Ea so I put it as it didn't say DONT put Ea
Original post by MaryamHera
what did everyone write for would the gas produced increase decrease or stay the same for the first few questions


Decrease because down the group from calcium the number of moles decreases
Original post by ineedA
Guys got the phosphorus and chlorine molecules, is it cause phosphorus has stronger induced dipole dipole cause more electrons ect?


Yes, I'm pretty sure that's right. I didn't actually put that, but I definitely remember reading that in the textbook :colondollar:
Instead of writing the alcohol is attached to 2 alkyl groups is attached to two C atoms Okay? Thanks
Reply 1017
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456CJ
2
I'm pretty sure it was 2-methylpropanoic acid as butanoic acid does not produce any secondary cations
Is oxidation of magnesium gaining electrons?
Original post by MaryamHera
Is oxidation of magnesium gaining electrons?


no oxidation is loss of electrons:

OILRIG

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