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Topic: Chemistry 11 Pressure and Finding Moles question  (Read 1988 times)

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Offline Ilikebugs

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Chemistry 11 Pressure and Finding Moles question
« on: April 22, 2019, 11:42:00 PM »
I am unfamiliar with how to solve this question. What is the relevant information and how do we use it to solve the question? I also am unsure of the units but 1 Pascal = 1Newton/square metre. Do we use PV=nRT?

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Offline sjb

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #1 on: April 23, 2019, 01:18:49 AM »
Consider typing the question out to help searching in the future. What are your thoughts?

Offline Ilikebugs

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #2 on: April 23, 2019, 03:53:21 PM »
The partial pressures of three gases in a 5.00 L cyinder at 1000 degrees C are as follows. CO2:239 kPa        H2:72kPa       H2O:106kPa       How many moles of CO2 are in the cylinder?

I think we can use Avogadros Law potentially?

Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #3 on: April 24, 2019, 02:53:25 AM »
If there were no other gases, just CO2, would you be able to solve the problem?
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Offline Ilikebugs

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #4 on: April 24, 2019, 09:08:23 AM »
(239000 Pa)(5 L)=n(8.314 J/(mol*K))(1273.15 K), so n=112.9 ish moles?

Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #5 on: April 24, 2019, 10:07:07 AM »
(239000 Pa)(5 L)=n(8.314 J/(mol*K))(1273.15 K), so n=112.9 ish moles?

You are on the right track, but if R is in J/(mol*K) units 5 (for the volume) is not in L.
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Offline AWK

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #6 on: April 24, 2019, 12:16:22 PM »
First of all H2 and CO2 can not exist side by side at this temperature. Moreover, at this temperature CO2 may partialy decompose to CO and O2
AWK

Offline Ilikebugs

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #7 on: April 24, 2019, 12:44:03 PM »
Isn't the unit for J/Pa metres cubed, which is the same as a litre?

Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #8 on: April 24, 2019, 01:30:41 PM »
No, meters yield cubic meter as a volume unit, that's not L.
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Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #9 on: April 24, 2019, 01:31:56 PM »
First of all H2 and CO2 can not exist side by side at this temperature. Moreover, at this temperature CO2 may partialy decompose to CO and O2

Hardly OP's fault.
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Offline Ilikebugs

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #10 on: April 24, 2019, 05:13:37 PM »
Oh I see, 1 cubic metre is 1000 cm so the answer is around 0.113 moles. Thanks!

Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #11 on: April 24, 2019, 05:56:40 PM »
Oh I see, 1 cubic metre is 1000 cm

No. 1 metre is 100 cm, 1 cubic metre is (100cm)3.

But judging from the result when you wrote 1000 cm you meant 1000 L.
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Offline Ilikebugs

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #12 on: April 26, 2019, 05:40:32 PM »
Just wondering, why were there other 2 gasses not necessary to find the answer?

Offline Borek

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Re: Chemistry 11 Pressure and Finding Moles question
« Reply #13 on: April 26, 2019, 06:24:35 PM »
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