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Topic: Stoic Gas Problem  (Read 5945 times)

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Offline jsp07001

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Stoic Gas Problem
« on: November 08, 2007, 09:00:13 PM »
Hey I just had a quick question any help/ advise would be really appreciated. The question is as follows... Acetylene, C2H2 and hydrofluoride react to give difluoroethane, C2H4F2. When 1.0 mol of C2H2 and 5.0 mol of HF reacted in a 10.0 L flask, how many mols difluoroethane will be produced?

I balanced the equation: C2H2 + 2HF --> C2H4F2

Now since there is only one mol of C2H2 I thought that it was the limiting reactant and therefore using the molar ratios from the balanced equation 1.0 mols difluoroethane would be produced. I was told this was wrong however and for the life of me I can't figure out how else you would do this... again any advice or hint as to where to start would be much appreciated.

Offline jsp07001

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Re: Stoic Gas Problem
« Reply #1 on: November 08, 2007, 10:22:13 PM »
Please anyone, this question is driving me insane I even asked a friend and they said that they agree with me and don't see how else you would do it...

Offline Sev

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Re: Stoic Gas Problem
« Reply #2 on: November 08, 2007, 10:41:45 PM »
It looks fine to me. 

Quote
When 1.0 mol of C2H2 and 5.0 mol of HF reacted in a 10.0 L flask, how many mols difluoroethane will be produced?

I am wondering why 10L volume is mentioned.

Offline jsp07001

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Re: Stoic Gas Problem
« Reply #3 on: November 08, 2007, 11:07:58 PM »
Well the bonus question after that asks what the pressure will be of the reactant if the reaction is taken place at STP... Re arranging the ideal gas law PV=nRT for P you could plug in your moles found, standard temp of 273.15K and the Volume to solve for P... Thats my best guess anyway. Anyone one have anyting to add to this? It is really driving me nuts. I get the feeling sometimes my teacher enjoys making students feel unintelligent.

Offline agrobert

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Re: Stoic Gas Problem
« Reply #4 on: November 08, 2007, 11:13:02 PM »
There should be 1.0 moles of 1,2-difluoroethene as you said and your pressure calculation is good.
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Offline Borek

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Re: Stoic Gas Problem
« Reply #5 on: November 09, 2007, 02:53:11 AM »
One mole it is, no doubt.
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Offline enahs

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Re: Stoic Gas Problem
« Reply #6 on: November 09, 2007, 09:44:25 AM »
Yes 1 mol, and your reasoning is correct. Unless you misread the information wrong. It is also possible your teacher said it was wrong due to improper use of significant figures when you showed him/her your answer.

Offline jsp07001

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Re: Stoic Gas Problem
« Reply #7 on: November 09, 2007, 02:56:29 PM »
Alright... well thanks for the replies at least I can feel confident in what I know now.

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