SI unit for P


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Chloe Qiao 4C
Posts: 65
Joined: Fri Sep 28, 2018 12:27 am

SI unit for P

Postby Chloe Qiao 4C » Sat Feb 02, 2019 1:45 pm

Can anyone tell me what is the SI unit we use for pressure? Is it atm or pa?

aisteles1G
Posts: 117
Joined: Fri Sep 28, 2018 12:15 am

Re: SI unit for P

Postby aisteles1G » Sat Feb 02, 2019 2:05 pm

The SI unit for Pressure is technically Pascals but the book uses atm for most calculations, and I don't think they expect you to know the conversion factor from atm to pascals which is 1 atm = 101325 Pa

Jonathan Omens 1K
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: SI unit for P

Postby Jonathan Omens 1K » Sat Feb 02, 2019 4:05 pm

In this class, use atm when reporting pressures.

Albert Duong 4C
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Joined: Fri Sep 28, 2018 12:17 am
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Re: SI unit for P

Postby Albert Duong 4C » Sat Feb 02, 2019 5:35 pm

Since atm is mostly used, the other gas constant R=.08206 L x atm/K/mol would most likely be used in questions involving PV=nRT.

Porus_Karwa_2E
Posts: 72
Joined: Fri Sep 28, 2018 12:24 am

Re: SI unit for P

Postby Porus_Karwa_2E » Sat Feb 02, 2019 9:16 pm

Our textbook uses bar mostly, but atm is technically the proper SI unite for pressure. Since there is only a 1% difference between bar and atm they are interchangeable though.

Harshita Talkad 4L
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

Re: SI unit for P

Postby Harshita Talkad 4L » Sat Feb 02, 2019 10:07 pm

I think we are supposed to use atm for pressure, and since there's a very small difference between atm and bars, the value with either of these units will be pretty much the same.

Alexandra Albers 1D
Posts: 61
Joined: Fri Sep 28, 2018 12:18 am

Re: SI unit for P

Postby Alexandra Albers 1D » Sat Feb 02, 2019 10:18 pm

So far, we have largely used atm for pressure measurements and have occasionally seen bar as well. From what I've seen, the units are only important for figuring out which version of the gas constant (R) we should use in calculations.


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