Chemistry Question Help (1 Viewer)

AsianFrustratio

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I'm kinda stuck with this question, mainly b)iii. I understand right now that two functional groups are required for condensation polymerisation to occur. However, the answers say that condensation reactions only occur with the monomer in b)iii, but only with another molecule/monomer. Could someone please explain why this happens? Any help would be appreciated :D
 

strawberrye

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This will be to the best of my understanding-so you may need to ask someone else to confirm this-perhaps you should recheck your answer again, because condensation polymerisation should also occur with bii)it has two functional groups, CL and OH, so joining with another identical molecule will result in elimination HCI molecule, for bi)propanol undergoes condensation reaction-i.e. react it under reflux(you will learn later in the year)with an alkanoic acid to form an ester-but this is NOT a condensation polymerisation process, my guess why it does not undergo condensation polymerisation is because it only has one functional group, i.e. the H on the other end is not considered a functional group(usually functional groups are more than one molecule, i.e. COOH, OH, NH2...)and because of this, it means it will join up with either identical or another molecule and that is the end of the story to form one single molecule, but condensation polymerisation should be a continuous process, hence there must be two functional groups (two sites for it to react) and for biii)it can't undergo condensation polymerisation with itself-because even though it has two functional groups, imagine the CL from the other molecule react to form chlorine gas-but you will be left with essentially a propane like unit-so the polymer would be like polypropane-which I don't think exist-and it will have a completely different name/structure than the original one-if you notice many condensation polymers they don't lose their two functional groups completely, they retain a part of one functional group in their final structure-i.e. OH-becomes O-hence you need another molecule with a different functional group to react continuously(I think most times the condensed molecule isn't a gas, but a liquid like water molecule or HCI molecule (and in case you don't know this-unsaturated molecules like propene only undergoes addition polymerisation, they don't undergo condensation ones)....hope this helps-but as I say, check with your teacher just in case:)
 

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