Which of the following are true statements about CO2 ?

Question

Which of the following are true statements about CO2 ?



a) The melting point of CO2 increases as pressure decreases


b) The critical point of CO2 occurs at 31oC and 73 atm


c) At −20oC and 12 atm CO2 is in the liquid state


d) At 20oC and 1 atm, solid CO2 will melt to liquid state


e) Above 31oC and 31 atm CO2 can not be compressed to the liquid state
under any amount of pressure

Answer 1

you should be given a graph of carbon dioxide's phase changes( temp vs. pressure), all the answers should be there.