I have tried every combination of terms that I can think of within PV=nRT to find nR. Here are the three expressions that I have come up with, none of which are correct based on the answer to this question...

nR = 100 * 0.01e-3 / 300 (the expression with kPa as the units of pressure)

nR = 100e3 * 0.01e-3 / 300 (the expression with Pa as the units of pressure)

nR = (100e3 / 1.013e5) * 0.01e-3 / 300 (the expression with atm as the units of pressure)

Help, please! I'm not sure what I'm screwing up on! Thanks to anybody who can help with this...

I think it will help you if you write the units with the numbers to make sure you have the result exressed in the units you need. I assume you want nR in units of Joules/K. I think I see an extraneous e-3 in the first two, and I have no idea why you tried the third one.

The e-3 is the conversion factor from m^3 to liters, which is why it's included. The third is because I've had success going from Pascals to Atmospheres before with this formula, and I'm a little n00bish with using it. Lemme re-write those with units...

nR = 100 kPa * 0.01 m^3 * (1 L / 1e-3 m^3) / 300 K
nR = 100e3 Pa * 0.01 m^3 * (1 L / 1e-3 m^3) / 300 K
nR = (100e3 Pa * (1 atm / 1.013e5 pa) ) * 0.01 m^3 * (1 L / 1e-3 m^3) / 300 K

I think I just found my mistake. I feel like an idiot for that one...