Calculate the density of propane C3H8 at 75 celcius and 800 torr?

Question

calculate the density of propane C3H8 at 75 celcius and 800 torr?

Answer 1

Okay I did this question twice and got a different answer from the other guy, so you might want to double check this one. Here's what I did anyway.

Use PV=nRT, and plug in n=m/M. Now you have PV=(mRT)/M, which you can rearrange to give m/V=(PM)/(RT). m/V is density, so now plug everything in (of course converting to the right units), and you should get:

density=m/V=1.627g/L

Answer 2

1622 g/L

Be sure you show your work to the professor.