Which Compound Cannot Be Liquefied by Compression, at a Temperature

Multiple Choice

Which compound cannot be liquefied by compression, at a temperature of 25.0°C?

A) C₂H₄, critical point: 9.9°C, 50.5 atm
B) CH₃Cl, critical point: 144.0°C, 66.0 atm
C) C₂H₂, critical point: 35.5°C, 61.6 atm
D) C₂H₆, critical point: 32.2°C, 48.2 atm
E) SO₂, critical point: 158.0°C, 78.0 atm