Use the phase diagram for CO2 in the question above to answer the following:
A sample of carbon dioxide is stored at 10,000 bar and 250 K. This sample is then decompressed to 1 bar at constant temperature. Then, at constant pressure it is heated to 400K. Next, it is compressed at constant temperature to 200 bar. According to the phase diagram, how many phase transitions has the sample of carbon dioxide gone through, and what is its final state?
a) 3, supercritical fluid b) 2, gas c) 3, liquid d) 2, supercritical fluid