I think the compound that has the highest boiling point is CCl4 This is because it has four Carbon-Chloride bonds , while the others have three, two and one and Carbon-hydrogen bonds. Carbon-Chloride bonds are stronger compared to the Carbon-hydrogen bond, therefore in this case the compound with more C-Cl will have more boiling point.
Explanation: Out of CH2Cl2, CCl4, CHCl3 and CH3Cl, CCl4 has highest boiling point.
Boiling point of the liquid is defined as the temperature at which the vapor pressure of the liquid becomes equal to the external pressure of the atmosphere.
It depends on the strength between the molecules and the large surface area.
As larger surface area will lead to the large experience towards the vander wall forces of attraction. Thus CCl4 has larger surface area than the other chlorocarbons . It will experience more vander wall forces of attraction than the other.
CO2 is carbon dioxide which is most famous for being in gas form so i would figure if it was exposed to freezing temperatures it would turn into a liquid then maybe a solid<span />
