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Topic: Condensation Polymerisation help, question in description  (Read 3228 times)

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Offline mynameisbobbyj

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Question is here: http://i.imgur.com/vdcjb.png
Can anyone please explain to me why the answer isn't 900 grams? (edit: oh, and what the answer actually is!) There is 50 mol of ethylene glycol and 50 mol of terephthalic acid, so there is no limiting reagent, don't I simply have to multiply 50 mol x 16 g mol, which would yield 900 grams?
Thanks for your time!   

Offline fledarmus

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Re: Condensation Polymerisation help, question in description
« Reply #1 on: May 12, 2012, 10:28:20 AM »
When I type 50*16 into my calculator, I don't get 900...

Offline ramboacid

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Re: Condensation Polymerisation help, question in description
« Reply #2 on: May 12, 2012, 04:39:40 PM »
Isn't the molar mass of water 18 g/mol, not 16 g/mol?
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Offline mynameisbobbyj

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Re: Condensation Polymerisation help, question in description
« Reply #3 on: May 12, 2012, 06:39:14 PM »
whoops, yeah 5- x 18 is 900 grams, but what is the correct answer?

Offline ramboacid

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Re: Condensation Polymerisation help, question in description
« Reply #4 on: May 12, 2012, 08:34:09 PM »
How many bonds does each terephthalic acid molecule make with ethylene glycol molecules by the condensation mechanism? Then, how many moles of bonds are made by 1 mole of terephthalic acid molecules with ethylene glycol molecules?
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Offline mynameisbobbyj

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Re: Condensation Polymerisation help, question in description
« Reply #5 on: May 13, 2012, 01:24:33 AM »
How many bonds does each terephthalic acid molecule make with ethylene glycol molecules by the condensation mechanism? Then, how many moles of bonds are made by 1 mole of terephthalic acid molecules with ethylene glycol molecules?

well between one TA molecule and one EG molecule, 1 bond, between two TA molecules and two EG molecules 3 bonds: EG-TA-EG-TA. Between 50 mol of EG and 50 mol of TA I presume it is 50 mol-1 molecule of water released, but because it is only 1 molecule it has no significance on the number?

Offline Borek

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Re: Condensation Polymerisation help, question in description
« Reply #6 on: May 13, 2012, 05:13:11 AM »
well between one TA molecule and one EG molecule, 1 bond, between two TA molecules and two EG molecules 3 bonds: EG-TA-EG-TA.

You are OK up to now.

How many moles of water produced per each mole of acid reacting?
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