ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: kenhung123 on May 09, 2010, 08:28:03 pm

Title: CONDENSATION-POLYMERISATION
Post by: kenhung123 on May 09, 2010, 08:28:03 pm: Does the oxygen in water have to be from the hydroxyl or caroxyl group? Or is it a totally random process?
Title: Re: CONDENSATION-POLYMERISATION
Post by: stonecold on May 09, 2010, 08:32:32 pm: I don't think it really matters, but if you want to get technical, then I believe it is from the carboxyl group.
Title: Re: CONDENSATION-POLYMERISATION
Post by: superflya on May 09, 2010, 08:33:48 pm: i dont think this really matters but id say the OH comes from the hydroxyl and the H from the carboxyl. leaving u with the ester linkage (COO).

>.>
Title: Re: CONDENSATION-POLYMERISATION
Post by: stonecold on May 09, 2010, 08:35:37 pm: haha, we both said a different thing. :P

I'm just saying what my teacher told me...
Title: Re: CONDENSATION-POLYMERISATION
Post by: Mao on May 09, 2010, 08:36:59 pm: OH comes from the carboxyl. But this mechanism is beyond VCE, so don't worry about it.
Title: Re: CONDENSATION-POLYMERISATION
Post by: superflya on May 09, 2010, 08:38:24 pm: lol yea i had no idea anyway :P
Title: Re: CONDENSATION-POLYMERISATION
Post by: Mao on May 09, 2010, 08:40:43 pm: http://en.wikipedia.org/wiki/Fischer_esterification
Title: Re: CONDENSATION-POLYMERISATION
Post by: stonecold on May 09, 2010, 08:43:56 pm: Just remember that carboxyl has 2 oxygens, and hydoxyl only has 1.

It is only fair that in the end they have 1 each. :P
Title: Re: CONDENSATION-POLYMERISATION
Post by: physics on May 09, 2010, 08:44:11 pm: OH from hyrdoxyl and the H from carboxyl
Title: Re: CONDENSATION-POLYMERISATION
Post by: superflya on May 09, 2010, 08:49:24 pm: Quote from: annahinh on May 09, 2010, 08:44:11 pm
OH from hyrdoxyl and the H from carboxyl

mao just corrected that ahah
Title: Re: CONDENSATION-POLYMERISATION
Post by: stonecold on May 09, 2010, 08:51:22 pm: Could you just imagine a question on this. It would be like:

In a condensation reaction between a carboxylic acid and an alkanol, water is formed. The oxygen in the water has come from:

a) the carboxylic acid
b) the alkanol
c) either the carboxylic acid or the alkanol as the reaction is random
d) the molecule with the lowest molecular weight

haha!
Title: Re: CONDENSATION-POLYMERISATION
Post by: physics on May 09, 2010, 08:53:40 pm: Quote from: superflya on May 09, 2010, 08:49:24 pm
Quote from: annahinh on May 09, 2010, 08:44:11 pm
OH from hyrdoxyl and the H from carboxyl

mao just corrected that ahah
serious? teacher told us it had to be like this XD
Title: Re: CONDENSATION-POLYMERISATION
Post by: happyhappyland on May 09, 2010, 08:55:04 pm: The O comes from the carboxy thats what I thought. WHen you form an amide group in proteins, it becomes NH-C=O and the OH is gone from the carboxy...
Title: Re: CONDENSATION-POLYMERISATION
Post by: kenhung123 on May 09, 2010, 08:58:56 pm: Coz in different textbooks they tend to highlight the O from different functional groups (jumping between hydroxy and carboxy)
Title: Re: CONDENSATION-POLYMERISATION
Post by: superflya on May 09, 2010, 09:07:10 pm: Quote from: kenhung123 on May 09, 2010, 08:58:56 pm
Coz in different textbooks they tend to highlight the O from different functional groups (jumping between hydroxy and carboxy)

yea it really doesnt matter.
Title: Re: CONDENSATION-POLYMERISATION
Post by: kenhung123 on May 09, 2010, 09:13:16 pm: Just wanted to clarify..
Title: Re: CONDENSATION-POLYMERISATION
Post by: Mao on May 10, 2010, 12:58:38 am: In acid catalysed esterification, the condensate is released from the carboxyl group.