The Student Room Group

OCR B Salter's Chemistry by Design F335 - 15th June 2015

Scroll to see replies

Original post by ASDuh97
Did anyone say methanol for the reagent of that amide group turning into a methyl group and ammonia being given out?


Yeah methanol
which structure of the monosubsitited phenol did you draw for the nmr? Just any phenol with a cl?
Original post by tealover96
Ahh crap I completely forgot to label it! That was one mark, I'm hoping?
For the drawing I did alcohol on top and cl on the bottom of the benzene ring? Because I thought that was the only isomer with three H environments


I did that but cl on top and OH at the bottom- shouldn't matter?
This paper was much better and much more accessible than that rotten first paper.

Anyone else get pH of 3.26 and 7.08?

There were 5 isomers of chlorophenol right? Also, the NMR one had the chlorine on the bottom carbon, I got.
Original post by Minecraft27
This paper was much better and much more accessible than that rotten first paper.

Anyone else get pH of 3.26 and 7.08?

There were 5 isomers of chlorophenol right? Also, the NMR one had the chlorine on the bottom carbon, I got.


Yes.

Don't know

No, 3 isomers
Original post by Solarburst
Yes.

Don't know

No, 3 isomers


Why only 3? There were 5 remaining carbons.
Original post by Priya265
I got 12.0 but I dont know if thats right


I got 12.0 as well but tbh I don't know how


Posted from TSR Mobile
What are people thinking for grade boundaries? Maybe around 85 for an A?
Original post by Priya265
I got 12.0 but I dont know if thats right


I got 12.0 too.
Original post by exams567
I did that but cl on top and OH at the bottom- shouldn't matter?


Yep it doesn't make a difference
Original post by tealover96
Ahh crap I completely forgot to label it! That was one mark, I'm hoping?
For the drawing I did alcohol on top and cl on the bottom of the benzene ring? Because I thought that was the only isomer with three H environments

I think it was 2 marks but not completely sure. I drew a phenols with a Cl atom2 carbons away
Original post by Minecraft27
Why only 3? There were 5 remaining carbons.


Think about it if you draw it on the '5th' carbon that's effectively the 1st carbon.

Draw it out and you'll see, always count the lowest number
Did anyone else get 12.0 for the pH question? It took soo long to do for 3 marks!
i got ph=10
The question was 25cm3 of acid reacted with 30cm3 of naoh with both being 0.02moldm-3
Original post by BrokenS0ulz
I think it was 2 marks but not completely sure. I drew a phenols with a Cl atom2 carbons away


What did we have to label ?


Posted from TSR Mobile
Original post by Minecraft27
Why only 3? There were 5 remaining carbons.


Because the others were reflections.
Original post by Minecraft27
Why only 3? There were 5 remaining carbons.


That was so poorly worded aha,

Just draw them out and count from the phenol with the lowest number
Some answers I can remember:
-pH: 3.3 (I think), 13 or 12
-33% for % by mass
-100% atom economy - no waste, environmentally friendly
-similarities: both form alkybenzene
-differences: Friedel-Crafts reactions normally used acyl chloride or halogenoalkane, but this was an alkene group
-Kekule structure favours electrophilic addition reactions. The other one shows that benzene undergoes electrophilic substitution reactions preserving the ring, so it is more stable.
-Increasing pressure would increase both the rate and equilibrium yield
-Increasing temperature would decrease the equilibrium constant
-methanol for one of the reagent
aldehyde, conc. Sulfuric acid, acidified potassium dichromate
Original post by king cobra
What did we have to label ?


Posted from TSR Mobile


The structure for which protons were responsible for Each peak in the nmr
Original post by The_Danimal
Did anyone else get 12.0 for the pH question? It took soo long to do for 3 marks!

I got 12

Quick Reply

Latest