11) If a quantity of this substance was at an initial pressure of 1.25 atm and a temperature of 300 C was lowered to a pressure of 0.25 atm, what phase transition(s) would occur? 12) If a quantity of this substance was at an initial pressure of 1.25 atm and a temperature of 0 C was lowered to a pressure of 0.25 atm, what phase transition(s) would occur? 13) If a quantity of this substance was at an initial pressure of 1.0 atm and a temperature of 200 C was lowered to a temperature of -200 C, what phase transition(s) would occur? 14) If a quantity of this substance was at an initial pressure of 0.5 atm and a temperature of 200 C was lowered to a temperature of -200 C, what phase transition(s) would occur? 15) If this substance was at a pressure of 2.0 atm, at what temperature would it melt? 16) If this substance was at a pressure of 2.0 atm, at what temperature would it boil? 7) If this substance was at a pressure of 0.75 atm, at what temperature would it melt? 3) If this substance was at a pressure of 0.75 atm, at what temperature would it boil? At what temperature do the gas and liquid phases become indistinguishable from each other? At what pressure would it be possible to find this substance in the gas, liquid, and solid phase?