Which of the bonding forces from the list below would need to be overcome to convert CO2?

from a liquid to a gas?





Which of the bonding forces from the list above would need to be overcome to convert NH3 from a liquid to a gas?





Which of the bonding forces from the list above would need to be overcome to convert CHCl3 from a liquid to a gas?








A) Ionic


B) Covalent


C) Dispersion


D) Dipolar


E) Metallic


F) Hydrogen


G) Molecular


H) None of the above





can be more than one answer*

Which of the bonding forces from the list below would need to be overcome to convert CO2?
There are always dispersion forces exist between molecules, so they are always need to be overcome to boil anything, but these very weak (albeit bonding) forces.


In case of CO2 this is pretty much it, since CO2 is not polar.


When something is polar (like CHCl3), there is also dipolar interaction (bonding), when negatively charged end of one molecule is attracted to positively charged end of another molecule. This attraction is stronger than dispersion.


Finally, if molecule has very electronegative elements (F, O, N) and hydrogen attached to them, then there is also going to be hydrogen bonding between molecules (in addition to dispersion and dipolar), when hydrogen of one molecule is attracted to electronegative element of neighboring molecule (like in the case of NH3).


So, there is a) dispersion interaction (bonding) in CO2,


b) dispersion and dipolar bonding in CHCl3, and c) dispersion, dipolar, and hydrogen bonding in NH3.





Remark: Usuallt term "bonding" is not very common in context of dispersion or dipolar (dipole-dipole is more correct term) attraction. Usually, such words as "forces" or "interactions" are used.
Reply:The answer is none. There are no bonds that are broken in the process of phase change. If this were not the case then when water boiled it would no longer be water. The process of a phase change is more a change in the average kinetic energy of a system, than a chemical change in the system.