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OCR A Chemistry F322 Chains, Energy and Resources Thu 19 Jan 2012

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Reply 600
Original post by otrivine
yh i got that for the final product and i wrote o2+o to give o3
o3 reversible o2+o
and then i got the same for final product ?
is that acceptable


ooo right i understand, so you didnt include the chlorine atoms at all then?
Reply 601
Original post by MEPLUS-->YOU
Did anyone get CH3OH+?
As peak?


i did it adds up to 34 or whatever the m/z of the fragment ion was
Original post by dee11
ooo right i understand, so you didnt include the chlorine atoms at all then?


no i was thinking of it but no? is this wrong though
Reply 603
Original post by superdentist
eurrh..dont remember , no i dont think so tbh


im sure there was, i dont rember the question too clearly, but it required us to add the any of the radicals together to give a neutral compound/ molecule?
Reply 604

Original post by Davo
i did it adds up to 34 or whatever the m/z of the fragment ion was


Wasn't it supposed to add upto 31?
Original post by Davo
i did it adds up to 34 or whatever the m/z of the fragment ion was


yeah 32.
wasn't it CH30? to add up to 31?
Reply 607
Original post by otrivine
no i was thinking of it but no? is this wrong though


it depepnds if the question was asking how the CFC in the question depleted the ozone, cause i dont remember too clearly now. but if so, then i think you might have needed to add the chlorines
Reply 608
Original post by andrewpeters
wasn't it CH30? to add up to 31?


yeah it was 31
Original post by dee11
it depepnds if the question was asking how the CFC in the question depleted the ozone, cause i dont remember too clearly now. but if so, then i think you might have needed to add the chlorines


snap! i loved the mechanisms 10 easy marks?

what did u get for the equation one for h+cl2 ?
what did u get for the boxes calculation where we had to fill in i really got confused i got a positive value? also, for the question on HCL what happens if pressure increases i said stays same ?
Reply 610
Anyone going to post the paper?
Reply 611
Also did one of the first questions ask for the molecular formulas, or the empirical formula of cyloheane? I put the empirical formula CH2
Reply 612
Original post by Tyles
how many structural isomers did that compound have at the start of the paper for 1 mark? it was either 4 or bluddy 8.?


was that for octan..if it was then i think it was 8, but i put 9, cos i though @time, u cud sub Br with Cl :confused:
Reply 613
Original post by otrivine
snap! i loved the mechanisms 10 easy marks?

what did u get for the equation one for h+cl2 ?
what did u get for the boxes calculation where we had to fill in i really got confused i got a positive value? also, for the question on HCL what happens if pressure increases i said stays same ?


for the radical sub i got
initiation:
Cl2---> 2Cl* (does UV need to be above the arrow for this????)
propagation:
Cl* +h2 --> HCl +H*
H* +Cl2 --> HCL + CL*
Termination
CL* +H* --> HCl (major)
Cl + Cl --> Cl2 (minor)
Original post by dee11
im sure there was, i dont rember the question too clearly, but it required us to add the any of the radicals together to give a neutral compound/ molecule?


:L maybee...not to my recollection though :frown:

what about the question about CFCS and why they are used?
Original post by faz_341
for the radical sub i got
initiation:
Cl2---> 2Cl* (does UV need to be above the arrow for this????)
propagation:
Cl* +h2 --> HCl +H*
H* +Cl2 --> HCL + CL*
Termination
CL* +H* --> HCl (major)
Cl + Cl --> Cl2 (minor)


thanks and for the one on depletion giving equations i put
the formulas with o radical
o2+o - o3
then the one which is reversible
then the final product is that right?
Reply 616
Original post by Bakr212
I got D and I. This is going so good so far


i'm sure it was G and H, because both where E/Z isomers of one another
Reply 617
Original post by otrivine
snap! i loved the mechanisms 10 easy marks?

what did u get for the equation one for h+cl2 ?
what did u get for the boxes calculation where we had to fill in i really got confused i got a positive value? also, for the question on HCL what happens if pressure increases i said stays same ?


yeah i think those mechanisms were easy also,

HZ +CL2? Was that calculating the enthalpy ?

the one with the boxes confused me quite abit, Im not even sure what i wrote in the end

Increasing the pressure means the same number of mollecules occupy a smaller area, so more collisins occur. so i wrote the rate increased :s-smilie:
Reply 618
Original post by c_subs
i'm sure it was G and H, because both where E/Z isomers of one another


:O really !
were G and H both alkenes also? i dont remember
Right just to clear some things up. For the structural isomers question is was 4. As the methyl group can have a cl attached, but that's the same as 1-chloro,2-methylheptane. So it's 4. I put 5 stupidly, because I didn't think about the methyl group being the same.

For the aldehyde/ketone, it said "Suggest a possible structure" that means you should get the mark for both.

As for the hydrolysing. Hydrolysis is when the OH attaches, have you not done Alkaline and Acid hydrolysis of halogenoalkanes before? I put that the C-Cl and C-F bonds are too strong to be broken just by water so increased temperature and acid/base is needed to weaken the bond.

Hydrolysis =/= dissolving sorry.

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