Carbon dioxide is sealed in a rigid 1.0 L container at 40 °C and 80 atm. On the particulate scale the average distance between molecules is only slightly larger than their diameters, and the molecules move freely throughout the entire volume of the vessel. Which phase classification most accurately describes the sample under these conditions?
a) Liquid CO2
b) A supercritical fluid of CO2
c) Solid CO2 (dry ice)
d) Gaseous CO2 under ordinary conditions