Go to first unread
Back
to top
A2 Chemistry People!
Watch this thread
High Stakes
Badges:
18
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
How are you finding it?
I've been revising organic chemistry and it's so damn long. Been revising acylation for the past hour and the addition-elimination reactions.
The kinetics, equilibria and acid/base stuff is a walk in the park because it's GCSE maths though. Tsodsdsihashdaskjdkashdasjhd
RonnieRJ - How good is your memory? How are you gonna pull off A2 Bio and A2 Chemistry without past papers? (ofc not hating, your method seems to be working since you did well but it's impressive to the past paper community. 
)
I've been revising organic chemistry and it's so damn long. Been revising acylation for the past hour and the addition-elimination reactions.
The kinetics, equilibria and acid/base stuff is a walk in the park because it's GCSE maths though. Tsodsdsihashdaskjdkashdasjhd
RonnieRJ - How good is your memory? How are you gonna pull off A2 Bio and A2 Chemistry without past papers?
(ofc not hating, your method seems to be working since you did well but it's impressive to the past paper community. 
)
0
reply
samb1234
Badges:
13
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report
#2
(Original post by High Stakes)
How are you finding it?
I've been revising organic chemistry and it's so damn long. Been revising acylation for the past hour and the addition-elimination reactions.
The kinetics, equilibria and acid/base stuff is a walk in the park because it's GCSE maths though. Tsodsdsihashdaskjdkashdasjhd
RonnieRJ - How good is your memory? How are you gonna pull off A2 Bio and A2 Chemistry without past papers? (ofc not hating, your method seems to be working since you did well but it's impressive to the past paper community. )
How are you finding it?
I've been revising organic chemistry and it's so damn long. Been revising acylation for the past hour and the addition-elimination reactions.
The kinetics, equilibria and acid/base stuff is a walk in the park because it's GCSE maths though. Tsodsdsihashdaskjdkashdasjhd
RonnieRJ - How good is your memory? How are you gonna pull off A2 Bio and A2 Chemistry without past papers?
(ofc not hating, your method seems to be working since you did well but it's impressive to the past paper community. )
0
reply
High Stakes
Badges:
18
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
(Original post by samb1234)
Too many conditions, colours etc
Too many conditions, colours etc
0
reply
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#4
Report
#4
Mechanisms are **** easy. NMR and polymers though are another story...
Also, the mark scheme is so annoyingly specific
Haven't looked at unit 5 yet tbh and don't really want to
Also, the mark scheme is so annoyingly specific
Haven't looked at unit 5 yet tbh and don't really want to
1
reply
samb1234
Badges:
13
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#5
Report
#5
(Original post by High Stakes)
I leave the "memory only and no concept" content for later because I can just sit down and memorise it.
I leave the "memory only and no concept" content for later because I can just sit down and memorise it.
0
reply
Applescruff
Badges:
11
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#6
Report
#6
Memorising the mechanisms is alright, you get it after a while.
For me it's proton NMR and 90% of transition metals that are going to ruin me
For me it's proton NMR and 90% of transition metals that are going to ruin me
0
reply
Dinasaurus
Badges:
22
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#7
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#8
Report
#8
(Original post by Dinasaurus)
Idek what acylation is? o.0
Idek what acylation is? o.0
0
reply
Dinasaurus
Badges:
22
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#9
Report
#9
(Original post by Manexopi)
It's nucleophilic addition elimination where you react alcl3 and an acyl chloride to form a reactive intermediate then react it with benzene. It can also be a reaction between an amine and acyl chloride/(carboxylic acid?) as well. Don't call it acylation in the exam though. Nucleophilic add elim is the ideal answer.
It's nucleophilic addition elimination where you react alcl3 and an acyl chloride to form a reactive intermediate then react it with benzene. It can also be a reaction between an amine and acyl chloride/(carboxylic acid?) as well. Don't call it acylation in the exam though. Nucleophilic add elim is the ideal answer.
0
reply
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#10
Report
#10
(Original post by Dinasaurus)
I don't think we do that in OCR then, never come across that.
I don't think we do that in OCR then, never come across that.
1
reply
High Stakes
Badges:
18
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#11
(Original post by Dinasaurus)
Idek what acylation is? o.0
Idek what acylation is? o.0
(Original post by Manexopi)
It's nucleophilic addition elimination where you react alcl3 and an acyl chloride to form a reactive intermediate then react it with benzene. It can also be a reaction between an amine and acyl chloride/(acid anhydride?) as well. Don't call it acylation in the exam though. Nucleophilic add elim is the ideal answer.
It's nucleophilic addition elimination where you react alcl3 and an acyl chloride to form a reactive intermediate then react it with benzene. It can also be a reaction between an amine and acyl chloride/(acid anhydride?) as well. Don't call it acylation in the exam though. Nucleophilic add elim is the ideal answer.
Acylation is simply adding an acyl group and we do this through introducing nucleophiles (reagents that attack positively charged carbon atoms) to our "acid derivatives" which are (for A-level anyway) Acid Chlorides and Acid Anhydrides. You simply need to learn their reactions with the following nucleophiles:
Ammonia to produce an amide.
Primary amine to produce an N-substituted amide.
Alcohol to produce an Ester.
Water to produce a Carboxylic acid.
In the reactions, all the nucleophiles listed above are initially neutral so they lose a H+ ion (proton), we call this Hydrogen the "active hydrogen".
Oh and you have to remember why we prefer to use Ethanoic Anhydride over Ethanoyl Chloride which is because:
- Cheaper.
- Less corrosive.
- Reacts less readily with water.
- Produces a less harmful byproduct!
1
reply
Amellia123
Badges:
17
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#12
Report
#12
(Original post by Manexopi)
Mechanisms are **** easy. NMR and polymers though are another story...
Also, the mark scheme is so annoyingly specific
Haven't looked at unit 5 yet tbh and don't really want to
Mechanisms are **** easy. NMR and polymers though are another story...
Also, the mark scheme is so annoyingly specific
Haven't looked at unit 5 yet tbh and don't really want to
Ikr, on the Chem4 2015 paper it asked for the molecular formula of TMS and apparently Si(CH3)4 was wrong (should have been SiC4H12
Unit 5 is quite bad... the ligand substation stuff is hard to remember and autocatalysis drives me insane
1
reply
girl :D
Badges:
12
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#13
Report
#13
any one doing or done their Chem isa's because those are what mess every thing up lol
1
reply
Dinasaurus
Badges:
22
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#14
Report
#14
I'm such a fool, I tried to rearrange the Henderson-Hasselbach formula because I remember I was able to simply it but I ended it just simplifying it down to pH=log(1/[H])
Which is the same as the original pH formula in the first place ;_;
Which is the same as the original pH formula in the first place ;_;
2
reply
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#15
Report
#15
(Original post by High Stakes)
I think you got aromatic chemistry in there with the benzene.
Acylation is simply adding an acyl group and we do this through introducing nucleophiles (reagents that attack positively charged carbon atoms) to our "acid derivatives" which are (for A-level anyway) Acid Chlorides and Acid Anhydrides. You simply need to learn their reactions with the following nucleophiles:
Ammonia to produce an amide.
Primary amine to produce an N-substituted amide.
Alcohol to produce an Ester.
Water to produce a Carboxylic acid.
In the reactions, all the nucleophiles listed above are initially neutral so they lose a H+ ion (proton), we call this Hydrogen the "active hydrogen".
Oh and you have to remember why we prefer to use Ethanoic Anhydride over Ethanoyl Chloride which is because:
- Cheaper.
- Less corrosive.
- Reacts less readily with water.
- Produces a less harmful byproduct!
I think you got aromatic chemistry in there with the benzene.
Acylation is simply adding an acyl group and we do this through introducing nucleophiles (reagents that attack positively charged carbon atoms) to our "acid derivatives" which are (for A-level anyway) Acid Chlorides and Acid Anhydrides. You simply need to learn their reactions with the following nucleophiles:
Ammonia to produce an amide.
Primary amine to produce an N-substituted amide.
Alcohol to produce an Ester.
Water to produce a Carboxylic acid.
In the reactions, all the nucleophiles listed above are initially neutral so they lose a H+ ion (proton), we call this Hydrogen the "active hydrogen".
Oh and you have to remember why we prefer to use Ethanoic Anhydride over Ethanoyl Chloride which is because:
- Cheaper.
- Less corrosive.
- Reacts less readily with water.
- Produces a less harmful byproduct!
Thanks for the info though :3 I did a pack of aromatic and amine questions in one so I'm abit confused rn
0
reply
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#16
Report
#16
(Original post by Amellia123)
I agree, theyre kind of a gift for me on the papers
Ikr, on the Chem4 2015 paper it asked for the molecular formula of TMS and apparently Si(CH3)4 was wrong (should have been SiC4H12
Unit 5 is quite bad... the ligand substation stuff is hard to remember and autocatalysis drives me insane
I agree, theyre kind of a gift for me on the papers
Ikr, on the Chem4 2015 paper it asked for the molecular formula of TMS and apparently Si(CH3)4 was wrong (should have been SiC4H12
Unit 5 is quite bad... the ligand substation stuff is hard to remember and autocatalysis drives me insane
Wait what? But what you said seems more specific?
Idek what ligand substitution is..or autocatalysis
I want to get unit 4 down before I even attempt unit 5. But unit 4 isn't going too well either. I have problems with polymers,amino acids and nmr/mass spec - doesn't help that I find them boring xD Also acid/base calcuations. I'm so confused why some of those titration/buffer calculations require you to take the total volume into account whilst others dont.
0
reply
High Stakes
Badges:
18
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#17
(Original post by Manexopi)
Ikr. The mark scheme is always the same as well 8)
Wait what? But what you said seems more specific?
Idek what ligand substitution is..or autocatalysis I want to get unit 4 down before I even attempt unit 5. But unit 4 isn't going too well either. I have problems with polymers,amino acids and nmr/mass spec - doesn't help that I find them boring xD Also acid/base calcuations. I'm so confused why some of those titration/buffer calculations require you to take the total volume into account whilst others dont.
Ikr. The mark scheme is always the same as well 8)
Wait what? But what you said seems more specific?
Idek what ligand substitution is..or autocatalysis
I want to get unit 4 down before I even attempt unit 5. But unit 4 isn't going too well either. I have problems with polymers,amino acids and nmr/mass spec - doesn't help that I find them boring xD Also acid/base calcuations. I'm so confused why some of those titration/buffer calculations require you to take the total volume into account whilst others dont.
0
reply
Rubato
Badges:
14
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#18
Report
#18
(Original post by High Stakes)
Depends on the volume added. It's all relative. Flick to page 48 in your A2 AQA book and look at the example. It's a change in 1%. Now, you can to be safe, always take into account the new volume...But since you're gonna be rounding up in the end a 1% change in vol won't have much of an affect. Whether you get 2.87 or 2.867
Depends on the volume added. It's all relative. Flick to page 48 in your A2 AQA book and look at the example. It's a change in 1%. Now, you can to be safe, always take into account the new volume...But since you're gonna be rounding up in the end a 1% change in vol won't have much of an affect. Whether you get 2.87 or 2.867
I got a completely different answer to the mark scheme (4.76)
http://filestore.aqa.org.uk/subjects...W-QP-JUN11.PDF
0
reply
thatcooldude2.0
Badges:
15
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#19
Amellia123
Badges:
17
Rep:
?
You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#20
Report
#20
(Original post by Manexopi)
Ikr. The mark scheme is always the same as well 8)
Wait what? But what you said seems more specific?
Idek what ligand substitution is..or autocatalysis I want to get unit 4 down before I even attempt unit 5. But unit 4 isn't going too well either. I have problems with polymers,amino acids and nmr/mass spec - doesn't help that I find them boring xD Also acid/base calcuations. I'm so confused why some of those titration/buffer calculations require you to take the total volume into account whilst others dont.
Ikr. The mark scheme is always the same as well 8)
Wait what? But what you said seems more specific?
Idek what ligand substitution is..or autocatalysis
I want to get unit 4 down before I even attempt unit 5. But unit 4 isn't going too well either. I have problems with polymers,amino acids and nmr/mass spec - doesn't help that I find them boring xD Also acid/base calcuations. I'm so confused why some of those titration/buffer calculations require you to take the total volume into account whilst others dont.
but apparently it was the 'molecular' formula That's a good idea actually - tackling unit 5 when you've aced unit 4 will make revision for the real thing a lot easier
Same, amino acids, polymers and NMR are so boring, to help you I recommend this site (it does OCR and AQA)
http://www.a-levelchemistry.co.uk/
And with bases/bufferes all I can suggest is revise from past paper questions to cover ever style of question.
If there are any questions you would like help with I would be more than willing to help you. Feel free to post them on here or PM/VM me
0
reply
X
Quick Reply
