Answer to Question #245001 in Physics for Diane

Question

Determine the density of oxygen gas (O2) at a pressure of 172,000Pa and temperature =-18 Celsius. State your answer to the nearest 0.001 kg/m3, follow the standard rounding rules in stating answer. Take the molar mass of molecular oxygen to be 32 g/mol, R=8.31 JK^-1mol^-1 and take the absolute zero to be -273 Celsius.

Answer 1

Write the universal gas law:

$$PV=\frac m{\Mu} RT,\\\space\\ P=\frac{\rho }{\Mu}RT,\\\space\\ \rho=\frac{P\Mu}{RT}=\frac{172000·0.032}{8.31·(273-18)}=2.596\text{ kg/m}^3.$$