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Simple arithmetic problems using PV = nRT or NkT. How do you know when to use pressure units in atmospheres or pascals? For example, in 1 particular problem they give you a pressure in units of Torr, volume in cubic cm and temp in Kelvin and ask for the number of molecules. Couldn't you convert Torr to atm, cm to L OR Torr to Pascals and cm to m. In the first case you get n number of moles and multiply by avagadro's number to get molecules. In the second case you use NkT to get the number of molecules directly, probably easier, but aren't both approaches correct?

Thanks

Dave

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# Ideal gas law problems: Pascals vs Atms?

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