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Year 1 Alevel Chemistry OCR homework help

So I’m currently doing a question for homework which is a multiple choice but I keep getting an answer that is not an option. I would appreciate any explanation/help as to where I have gone wrong!

The question:
What is the pressure of 3 moles of gas in a 520dm3 container at a standard temperature? The gas constant is 8.314Jmol-1K-1 .
A) 14.3 Pa
B) 1199 Pa
C) 14.3 kPa
D) 14300 kPa

I used the pV=nRT equation to solve my answer. I’ve put the standard temperature as 273 K and I converted 520dm3 into m3 then put this all into my equation to get 13094.55 Pa. Obviously this is not correct so can someone please help me as what I did incorrect.

Thanks!

Reply 1

Original post
by hmn123
So I’m currently doing a question for homework which is a multiple choice but I keep getting an answer that is not an option. I would appreciate any explanation/help as to where I have gone wrong!

The question:
What is the pressure of 3 moles of gas in a 520dm3 container at a standard temperature? The gas constant is 8.314Jmol-1K-1 .
A) 14.3 Pa
B) 1199 Pa
C) 14.3 kPa
D) 14300 kPa

I used the pV=nRT equation to solve my answer. I’ve put the standard temperature as 273 K and I converted 520dm3 into m3 then put this all into my equation to get 13094.55 Pa. Obviously this is not correct so can someone please help me as what I did incorrect.

Thanks!


Try using T = 298 K and then converting your answer to kPa by dividing it by 1000

Reply 2

Original post
by hmn123
So I’m currently doing a question for homework which is a multiple choice but I keep getting an answer that is not an option. I would appreciate any explanation/help as to where I have gone wrong!
The question:
What is the pressure of 3 moles of gas in a 520dm3 container at a standard temperature? The gas constant is 8.314Jmol-1K-1 .
A) 14.3 Pa
B) 1199 Pa
C) 14.3 kPa
D) 14300 kPa
I used the pV=nRT equation to solve my answer. I’ve put the standard temperature as 273 K and I converted 520dm3 into m3 then put this all into my equation to get 13094.55 Pa. Obviously this is not correct so can someone please help me as what I did incorrect.
Thanks!

Instead of the actual temperature, you've put the conversion rate of 0*C to *K, which is 273*K. Very similar numbers, but it does need to be learned. As mentioned by TypicalNerd, the standard temperature is 298*K, or 25*C.

Reply 3

Original post
by TypicalNerd
Try using T = 298 K and then converting your answer to kPa by dividing it by 1000


thanks so much!

Reply 4

Original post
by zmp903
Instead of the actual temperature, you've put the conversion rate of 0*C to *K, which is 273*K. Very similar numbers, but it does need to be learned. As mentioned by TypicalNerd, the standard temperature is 298*K, or 25*C.


I understand now, thank you so much!!

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