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OCR Chemistry F322~ 4th June 2013~ AS Chemistry

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Oh **** can you put low temperature for fermentation? And enzyme for yeast??

Also I got alcohol and an aldehyde!! How many marks would I lose?? I guess two for the wrong product right?

Oh wells.

Would hydrogen atoms will be diagonal to form a E isomer be accepted? Instead of saying opposite sides ..

I think I lost around 10 marks max.

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Reply 3201

yodawg321

Someone put the paper up! Everyone will love you foreverrr

Reply 3202

Pataiiii

Original post by motivatedshroom

For the free radical substitution could you not do CH3. +I2 --> CH3I + I.
As the second propagation step
Because I2 could be formed in a termination step? I. + I. --> I2
oh my

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I don't think you could because no HBr would be able to form.

Reply 3203

Smko

you know the fermentation one... could you say yeast + 37 or did you have to say anerobic? :frown:

Reply 3204

the A* guy

Original post by Smko

how you know 94 for full? :smile:

In June 2011 it was 94, this email proves it.

https://www.whatdotheyknow.com/request/raw_mark_for_100ums_in_biology_a?unfold=1

Reply 3205

zangorou

Original post by Pataiiii

It was 240dm cubed so it was 240/24 = 10moles then 5 x delta H which give you something in the 800's

I did that, but realised the units were in kJ instead of kJ/mol. So I converted the enthalpy into kJ then multiplied it..

Reply 3206

alice.o123

Original post by motivatedshroom

For the free radical substitution could you not do CH3. +I2 --> CH3I + I.
As the second propagation step
Because I2 could be formed in a termination step? I. + I. --> I2
oh my

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you should be able to have that because all the products of the different steps will be present throughout, so it is possible, though it's not the most obvious propagation step. the only thing that might mean it wouldn't be right is if the I2 molecule is split into radicals the same way as IBr is, before it has a chance to react with the CH3.

Reply 3207

the A* guy

Does anyone want me to upload the paper?

Reply 3208

Liberty.

In the infrared question, I was so proud of myself for finding the exact molecular formula, drew out a aldehyde and left it at that.
Completely forgot about keytones :facepalm:

Reply 3209

niceguy95

Original post by motivatedshroom

For the free radical substitution could you not do CH3. +I2 --> CH3I + I.
As the second propagation step
Because I2 could be formed in a termination step? I. + I. --> I2
oh my

Posted from TSR Mobile

I'm pretty sure it was

IBr --------> I + Br. Initiation by homolytic fission

Ch4 + Br --------> ch3 + hbr

Ch3 + IBr -------> ch3I + Br

Both. Being propagation

Ch3. + Br ------> ch3br termination

Not sure why people are getting I2 if it asked how ch3I and Hbr was formed

Reply 3210

Gingerstudent999

For the Hess cycle question, my friend got -1444 but I got like -4000 something, how did they get -1444 ?

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Reply 3211

jackitsme

Original post by jamesfancourt

I got like 4500 something amongst those lines

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yeah i got -4000 and something :L

Reply 3212

joe1545

Original post by irfymahmood

what did people put for the last question on increase in tempreture and a catalyst added?

I split the question into two bits, temperature and catalyst, drew two diagrams for each, both correct, then said how a decrease in activation means more molecules now have the activation energy, and showed the increase by shading the diagram, and the same for temp so rate would increase