Question

Answer this based on the the P-T phase diagram of CO₂: CO₂ is heated to a temperature 70° C and compressed isothermally. What changes in its properties do you expect to observe?

Answer 1

see figure, here we are shown pressure and temperature graph of CO2 .

we know , critical temperature of carbon dioxide gas is 31°C. and it is clear that 70°C is higher than the critical temperature of CO2, so, the CO2 gas cannot be converted into liquid state on being compressed isothermally at 70°C. It will remain in the vapour state. However, the gas will deviate from its perfect gas behaviour with increasing pressure.