h26
Badges: 12
Rep:
?
#1
Report Thread starter 3 years ago
#1
Stuck on part iii please help
Name:  sa.PNG
Views: 142
Size:  43.7 KB
Attachment 750586750588
STuck on part iii please help
Attached files
0
reply
millbaker
Badges: 9
Rep:
?
#2
Report 3 years ago
#2
Okay so I think... the reaction to form d is condensation so u need to remove a water molecule (you know it’s not to do with the NH2 as it says it needs to be free in D) so on valine there is only one OH so that’s fine, it says it is an Ester so I think u pick the OH that is at the top bc then when you remove H2O from the 2 OH groups you are left with c=o (from valine) and o .... Ester group, the other OH becomes O And therefore forms another Ester group and this O is available for the next monomer to attach
0
reply
millbaker
Badges: 9
Rep:
?
#3
Report 3 years ago
#3
I hope that’s right/ makes sense (I am also an a level chem student lol)
1
reply
h26
Badges: 12
Rep:
?
#4
Report Thread starter 3 years ago
#4
(Original post by millbaker)
Okay so I think... the reaction to form d is condensation so u need to remove a water molecule (you know it’s not to do with the NH2 as it says it needs to be free in D) so on valine there is only one OH so that’s fine, it says it is an Ester so I think u pick the OH that is at the top bc then when you remove H2O from the 2 OH groups you are left with c=o (from valine) and o .... Ester group, the other OH becomes O And therefore forms another Ester group and this O is available for the next monomer to attach
Thanks but I think you're talking about part ii. I am stuck with part iii where you even get secondary amide groups -they're reacting the Ester group with the amine group of D which is rather weird.
can you please help with this?
0
reply
charco
Badges: 17
Rep:
?
#5
Report 3 years ago
#5
You are told that the amine group is untouched.

Hence valine reacts using its carboxylic acid group, -COOH
Therefore it must condense with the hydroxyl group of the 2-hydroxypropanoic acid, leaving the carboxylic acid group untouched

This produces a molecule with an amine group on one end and a carboxylic acid group on the other.

This monomer can then polymerise by forming amide groups with other monomers.

nH2N-R-COOH --> -[-HN-R-CONH-]-n-
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Do you think receiving Teacher Assessed Grades will impact your future?

I'm worried it will negatively impact me getting into university/college (144)
42.73%
I'm worried that I’m not academically prepared for the next stage in my educational journey (39)
11.57%
I'm worried it will impact my future career (28)
8.31%
I'm worried that my grades will be seen as ‘lesser’ because I didn’t take exams (72)
21.36%
I don’t think that receiving these grades will impact my future (34)
10.09%
I think that receiving these grades will affect me in another way (let us know in the discussion!) (20)
5.93%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise