## Ideal gas constant R

$PV=nRT$

Maayan Epstein 14B
Posts: 39
Joined: Fri Sep 28, 2018 12:20 am

### Ideal gas constant R

When do I plug in the ideal gas constant, R, as 0.0825, and when do I plug it in as 8.314?
Not sure when to use which!

Charles Hood Disc 1C
Posts: 39
Joined: Fri Sep 28, 2018 12:19 am

### Re: Ideal gas constant R

Look at the units you are dealing with, the constants have different units. So if you don't know try looking at what units you are using and comparing them to the units of the gas constants.

Heesu_Kim_1F
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am

### Re: Ideal gas constant R

I think it just depends on which units you are working with: R = 0.08206 L x atm x K^-1 x mol ^-1 and R = 8.314 J x K^-1 x mol^-1.

Jake Gordon 1A
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: Ideal gas constant R

The units for the small constant given above are atm L per mol K and the other constant is J per mol K, since the mol K in the denominator is consistent, it depends on whether you are using pressure and volume( atm and L) or energy (J or kJ) in the overall mathematic expression.

Maayan Epstein 14B
Posts: 39
Joined: Fri Sep 28, 2018 12:20 am

### Re: Ideal gas constant R

Thank you for the responses!

Tony Chung 2I
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: Ideal gas constant R

That depends on the units that you are given and are working with.

Carine Tamamian 2B
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Ideal gas constant R

Depends on the units! L or J

jocelyntzeng
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

### Re: Ideal gas constant R

just look at the units and see which one to use

Mark 1D
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

### Re: Ideal gas constant R

depends on the units in the question

Jacqueline Duong 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:28 am

### Re: Ideal gas constant R

Yeah, it depends on the question and what units you would need to be able to cancel out

Callum Guo 1H
Posts: 110
Joined: Fri Aug 02, 2019 12:15 am
Been upvoted: 1 time

### Re: Ideal gas constant R

It depends if the pressure given is in atm or pascals