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Topic: Find Moles of NH3  (Read 2527 times)

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Offline eleventhxhour

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Find Moles of NH3
« on: November 03, 2014, 04:29:04 PM »
How many moles of NH3 must be placed in an evacuated 0.250 L reaction vessel at constant temperature to yield an equilibrium concentration of 1.50 mol/L for N2?

N2 (g) + 3H2(g)  ::equil::  2NH3(g)

k = 8.00


So I'm not really sure how to do this question. I thought about making an ICE table for the reaction, but I don't know what to put in it. I know that the E(equilibrium concentration) for N2 is 1.50, but I'm not sure what else to add...

Thanks!

Offline Borek

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Re: Find Moles of NH3
« Reply #1 on: November 03, 2014, 06:50:49 PM »
ICE table is a good idea. Just your unknown (x) will be in the first line (initial).
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Offline eleventhxhour

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Re: Find Moles of NH3
« Reply #2 on: November 05, 2014, 08:35:29 PM »
I'm still confused what to do next?
The initial concentration of N2 would be x...and then?

Offline Borek

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Re: Find Moles of NH3
« Reply #3 on: November 06, 2014, 03:05:26 AM »
No, initial concentration of N2 is zero. You start with pure ammonia.
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Offline Hunter2

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Re: Find Moles of NH3
« Reply #4 on: November 06, 2014, 04:15:45 AM »
First calculate the mole of N2 in the vessel. If you know this you can also see on the equation how much hydrogen has to be obtained. On the other side you can see how much ammonia was decomposed to create  the nitrogen and the hydrogen. This you put in the equation . For ammonia its (x - decomposed NH3)2.

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