Aqa chem4 15th june 2011 (resit) thread

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Yep, that something being a ketone.

What did you put for distinguishing ester and carboxylic acid? and what about the others?

I'm not sure I got them all correct. :s-smilie:

caboxylic ACID (hint!)

NH3 for substitution of chloride in acyl chloride then silver nitrate.

Oxidation under reflux - primary alcohol to carboxylic ACID so test with universal indicator like in the first test

Reply 1021

Ramses II

I did NaHCO3 for the acid, causing CO2 effervescence.
For the Acyl chloride, there is a vigorous reaction and white precipitate with AgNO3.
Primary alcohol I did acidified K2Cr2O7, orange to green.

Reply 1022

Zakir

Original post by Ramses II

I did NaHCO3 for the acid, causing CO2 effervescence.
For the Acyl chloride, there is a vigorous reaction and white precipitate with AgNO3.
Primary alcohol I did acidified K2Cr2O7, orange to green.

yeh thats what i did..

think thats 9 marks (atleast) in the bag! :wink:

Reply 1023

i3kel

Original post by Turnerthecentury

1) 3,3-dimethylbutan-1-ol
4 peaks
triplet

2) 1,1-dimethylbutan-1-ol
4 peaks
singlet

the second one is actually pentane, a methyl and the end of a chain isnt separate..its part of the chain, I thought it was odd theyd give 2 butanols in the same naming question. so it was actually (and this is going off what you wrote I cant remember exactly) 2- methylpentan-2-ol

Reply 1024

addvic

Original post by Ramses II

I did NaHCO3 for the acid, causing CO2 effervescence.
For the Acyl chloride, there is a vigorous reaction and white precipitate with AgNO3.
Primary alcohol I did acidified K2Cr2O7, orange to green.

for the first one (ester and carboxylic acid) i put phorphorus pentachloride.. ester has no reaction and carboxylic acid produces steamy white fumes (HCl)... does that seem acceptable? i know there might be a few ways of doing each one so there may not be a definitive correct answer.. but i havent seen anyone else put that reagent!

Reply 1025

addvic

Original post by Casshern1456

Benzene-1,2-diolic acid

3-hydroxy, 2-aminopropanoic acid. (could be 2-amino, 3-hydroxy-) I think they allow both?

i dont think they do allow both... or they shouldnt cos it should be the lowest numbering system!! and you have to count the C in the carboxylic acid group as the first carbon

Reply 1026

A-level11

I thought it went ok but listening to everyones answers is making me panic. Tho still think I am going to do awful because I ran out of time and never got the last three pages done. Always struggle with time in my chemistry papers

Reply 1027

addvic

Original post by A-level11

just focus on the next one, you cant change what you've already done but you can prepare as well as possible for the next one!

Reply 1028

508836

What did people put for the colour change and the molecular ion?

I think I made a small mistake on the molecular ion i think the free radical was supposed to be OCH3CH2 but I put CH3CH2 :frown:

(edited 12 years ago)

Reply 1029

508836

Original post by Ramses II

I did NaHCO3 for the acid, causing CO2 effervescence.
For the Acyl chloride, there is a vigorous reaction and white precipitate with AgNO3.
Primary alcohol I did acidified K2Cr2O7, orange to green.

Correct

Reply 1030

FristyKino

Original post by T-Toe

What did people put for the colour change and the molecular ion?

I think I made a small mistake on the molecular ion i think the free radical was supposed to be OCH3CH2 but I put CH3CH2 :frown:

It was supposed to be purple to yellow.
Me being so stupid I just wrote yellow (think colour change is supposed to be from X-->Y) :frown:

Reply 1031

508836

Original post by FristyKino

It was supposed to be purple to yellow.
Me being so stupid I just wrote yellow (think colour change is supposed to be from X-->Y) :frown:

On really, I thought it was a mixture of purple and yellow. So we had to find the colour in-between purple or yellow, I put pink :facepalm2:

. Oh well..

How'd you find the paper?

Reply 1032

Zakir

Original post by T-Toe

On really, I thought it was a mixture of purple and yellow. So we had to find the colour in-between purple or yellow, I put pink :facepalm2:

. Oh well..

How'd you find the paper?

Which question was this? The purple and yellow...

Reply 1033

508836

Original post by Zakir

Which question was this? The purple and yellow...

First page. After the one which we had to work out which titration graph was which.

Reply 1034

Zakir

Original post by T-Toe

First page. After the one which we had to work out which titration graph was which.

Oh ok...
Yeh thats what i got...the bromosomething purple and yellow, thats gd! :smile:

Reply 1035

508836

Original post by i3kel

Did we have to name the both molecules? I only wrote the peaks and nmr

For the 2nd one I got quadrat/4 (n+1)

Reply 1036

508836

Original post by Zakir

Oh ok...
Yeh thats what i got...the bromosomething purple and yellow, thats gd! :smile:

I got bromosomething too.

What did you get for molecular ion? m/z=177?

(edited 12 years ago)

Reply 1037

FristyKino

Original post by T-Toe

On really, I thought it was a mixture of purple and yellow. So we had to find the colour in-between purple or yellow, I put pink :facepalm2:

. Oh well..

How'd you find the paper?

It was ok. think i made some silly mistakes. exam pressure :mad:

Reply 1038

lou12

How many marks was the long question about benzene worth?Was it 4 or 6 marks?
And did it ask to explain the stability AND explain the evidence given? By talking about the delocalised system etc.