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OCR Chemistry B (Salters) F334/F335 Exam Thread 2016 (14th/22nd June)

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Original post by B50les
I got 4 for y


I also got 2 :/ I dont know if its right though...? But my logic was that if FeOy exists, the Fe can only be Fe3+ or Fe2+ and if it was Fe3+ then you'd have to have 9 oxygens which sounds quite unreasonable...? You might be right though it was only a guess! D:
Reply 761
Original post by Zuzuvela
No it would be Nitrogen (I) Oxide . N2O. Colourless Gas so it was trick question

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I put that too
Original post by HecTic_H
Anyone smart enough and confident enough to make an unofficial Mark scheme?


You might as well become a comedian :wink: Of course no one is gonna be able to make an unofficial mark scheme its OCR!!! 😂😂😂
Original post by KatieAlicexxx

I put that as well 😂
Original post by noname102
Anyone remember the temperature one - min temperature or something?


the entropy one? i think i got 480 or something similar :smile:
a few questions i can remember.... reply and add your answers

moleculuar forumula?
saturated functional group?
strange hydrogen bonding question
kc units
if reaction was exo/endo thermic
activation enthalpy question
pH
How it acts as buffer
pH when the salt is twice acid or whatever
bond angle
electon arrangments (last question)
how to make compound B from E (reagents)
temperature for reaction to occur?
value of n?
value of y?
colour
why iron is coloured
electronic energy levels question
number of hydrogen environments
the freezing temperature
overall reaction from the 5 different reactions
atom economy
nh4no3 decomposition
glc question
reagents for benzene nitration
what effect imatanib has on active site
why calcium ions are ..... (above question about drawing calcium ion hydrated)
question about kc and wanting to find concentration of water
moleculuar forumula:

saturated functional group: Alkane.

strange hydrogen bonding question:
Standard AS answer on how hydrogen bonds form. That molecule didn't have any.

Kc units: top amd bottom cancel out so no units. Same amount of moles on both side

if reaction was exo/endo thermic : Exothermic as increased temp decreased Kc. More reactants

Why one ion has more exothermic solubility than other: More charge dense. More strongly hydrated. More bonds made. Bond making exothermic.

activation enthalpy question: minimum enthalpy required for reaction to take place. Catalysts provide alternative reaction route with lower Ea
pH

How it acts as buffer

pH when the salt is twice acid or whatever: 9.55

bond angle 109 standard answer + nitrogen has lone pair

electon arrangments (last question) [Ar] 3d5

how to make compound B from E (reagents)

temperature for reaction to occur?
value of n? 1
value of y? 4
colour: yellow

why iron is coloured

electronic energy levels question

number of hydrogen environments : 3 environments
the freezing temperature: -1.9c

overall reaction from the 5 different reactions: can't remember exactly but it was an ionic substitution

atom economy 100% no waste

nh4no3 decomposition NH4NO3 --> 2H2O + N2O

N2O : Nitrogen (I) Oxide . Colourless Gas
glc question:

reagents for benzene nitration HNO3, Conc H2SO4 and

what effect imatanib has on active site. Blocks it; Reduces enzyme activity

question about kc and wanting to find concentration of water
Original post by Zuzuvela
moleculuar forumula:

saturated functional group: Alkane.

strange hydrogen bonding question:
Standard AS answer on how hydrogen bonds form. That molecule didn't have any.

Kc units: top amd bottom cancel out so no units. Same amount of moles on both side

if reaction was exo/endo thermic : Exothermic as increased temp decreased Kc. More reactants

Why one ion has more exothermic solubility than other: More charge dense. More strongly hydrated. More bonds made. Bond making exothermic.

activation enthalpy question: minimum enthalpy required for reaction to take place. Catalysts provide alternative reaction route with lower Ea
pH

How it acts as buffer

pH when the salt is twice acid or whatever: 9.55

bond angle 109 standard answer + nitrogen has lone pair

electon arrangments (last question) [Ar] 3d5

how to make compound B from E (reagents)

temperature for reaction to occur?
value of n? 1
value of y? 4
colour: yellow

why iron is coloured

electronic energy levels question

number of hydrogen environments : 3 environments
the freezing temperature: -1.9c

overall reaction from the 5 different reactions: can't remember exactly but it was an ionic substitution

atom economy 100% no waste

nh4no3 decomposition NH4NO3 --> 2H2O + N2O

N2O : Nitrogen (I) Oxide . Colourless Gas
glc question:

reagents for benzene nitration HNO3, Conc H2SO4 and

what effect imatanib has on active site. Blocks it; Reduces enzyme activity

question about kc and wanting to find concentration of water


What was the -CH3O group on the benzene then?
Reply 768
Original post by Loyota
What was the -CH3O group on the benzene then?


Ether?
Original post by _MAT_
Ether?


Therefore it can hydrogen bond by acting as a hydrogen bond acceptor.
Reply 770
Original post by Loyota
Therefore it can hydrogen bond by acting as a hydrogen bond acceptor.


That's what I put, it can form a few hydrogen bonds but not many when paired with another molecule which is able to form hydrogen bonds
Original post by _MAT_
That's what I put, it can form a few hydrogen bonds but not many when paired with another molecule which is able to form hydrogen bonds


Yes :smile:
Reply 772
Original post by Loyota
Yes :smile:


Good good :smile:
Reply 773
Original post by Zuzuvela


number of hydrogen environments : 3 environments
the freezing temperature: -1.9c



I got 6 environments and -2.9 for these two. Did you forget that it was CaCl2 so 3 moles of particles rather than the two in NaCl?
Original post by Bruhh
I got 6 environments and -2.9 for these two. Did you forget that it was CaCl2 so 3 moles of particles rather than the two in NaCl?


6 hydrogen environments is wildly wrong. NMR with more than 4 peaks just doesn't happen at A2.
You may be correct -1.9 was an answer that a majority got. It wasn't clear what was meant by particles dissolved (already dissolved or to be dissolved) whether it was talking about the ions or the solute overall. Some of those answers were suggested btw not necessary what I put.

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Original post by Zuzuvela
6 hydrogen environments is wildly wrong. NMR with more than 4 peaks just doesn't happen at A2.
You may be correct -1.9 was an answer that a majority got. It wasn't clear what was meant by particles dissolved (already dissolved or to be dissolved) whether it was talking about the ions or the solute overall. Some of those answers were suggested btw not necessary what I put.

Posted from TSR Mobile


Wildly correct more like.
Reply 776
Original post by Zuzuvela
6 hydrogen environments is wildly wrong. NMR with more than 4 peaks just doesn't happen at A2.
You may be correct -1.9 was an answer that a majority got. It wasn't clear what was meant by particles dissolved (already dissolved or to be dissolved) whether it was talking about the ions or the solute overall. Some of those answers were suggested btw not necessary what I put.

Posted from TSR Mobile


Hmm okay, but I thought if you had a group on the benzene the environments were slightly different like in this image:

Reply 777
anyone else get 9.5 or something for the pH ones? lol I'm props wrong i hate calculations
Reply 778
Original post by Bruhh
Hmm okay, but I thought if you had a group on the benzene the environments were slightly different like in this image:




not sure why you'd have one hydrogen environment with 2 hydrogens in that are opposite sides of the ring?
Reply 779
Original post by millss
not sure why you'd have one hydrogen environment with 2 hydrogens in that are opposite sides of the ring?


Well its symmetrical so thats where the opposite sides comes from. The image is from a UCLA pdf on NMR.

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