Ideal Gas Equation: Calculating R in PV=nRT

[Dodabby]

Homework Statement

The ideal gas equation, PV=nRT, may have the following units:
P is given in bar (bar)
V is given in m3 (cubic meters)
N is given in mol (moles)
T is given in K (kelvin)

Which value of R would you use for the calculation if you were using the above units for the other variables in the calculation?

Homework Equations

Dont have any.

The Attempt at a Solution

I have no attempt at the solution as i honestly do not understand how to come to a conclusion. I am a first year university student, having just started a degree in Biochemistry - and i have three basic chemistry modules to complete before i can get onto Biochemistry.

This being a career change for me at age 34, and not having done science in school, i am really stuck and have been battling on this question for a week now.

Any help would be greatly appreciated - just an explanation of where to start would be of great help.

Thanks!

 

[Borek]

Solve for R - and replace given symbols (P, V, n, T) with units.

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methods

 

[nobahar]

The gas constant's value is determined by its units. If you alter the units you need to alter the value of the constant also. The gas constant is joules per (kelvin x mol). If you multiply pressure in pascals by volume in metres you get joules. Since your volume is in metres already, you need to find out the relationship between pascals and bar.
At least, I think that's correct...

 

[nobahar]

Solve for R - and replace given symbols (P, V, n, T) with units.

You beat me Borek!
Is what I said reliable?

 

[Borek]

You are right. OTOH once you know your units you can easily check correct value - see http://en.wikipedia.org/wiki/Ideal_gas_constant

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[Dodabby]

Thank you for the response :)

Problem is - the question is exactly as i typed it. There are no units given, at all. Hence why i am stumped :/

Have they perhaps made a mistake, or am i really being clueless?

 

[Borek]

P is given in bar (bar)
V is given in m3 (cubic meters)
N is given in mol (moles)
T is given in K (kelvin)

No units?

--
methods

 

[nobahar]

Thanks Borek.
Dodabby, do you mean R? R has units, also. R is the Gas Constant:
http://en.wikipedia.org/wiki/Gas_constant

 

[Bohrok]

You could start with $$R = 0.0821 \frac{L\cdot atm}{mol\cdot K}$$ and convert the pressure and volume to the other units.