First of all, the process of sublimation is the direct change from solid state to gaseous. Iodine molecules have a desperation force between them which is the weakest of the bonds. Therefore, when subjected to heat until the temperature reaches boiling point, the bond will break easily and without passing through liquid state, the iodine solid will sublime into iodine gas .
1 Comment
Nitrogen (N2) and Oxygen (O2) are non polar molecules and therefore the intermolecular force between is the weakest, which is the dispersion force. The low boiling point is due to this force between the molecules which causes the bond to be easily broken.
Both molecules, the hydrogen sulfide molecule and the water molecule, are polar. Therefore, 2H2S bonded together and 2H2O bonded together creating a dipole-dipole force between them. But in 2H2O the dipole-dipole force is hydrogen bonding with Oxygen since Oxygen is more elegronegative therefore the intermolecular force between 2H2O is hydrogen bond. Moreover, to form a hydrogen bond, hydrogen must bond with Oxygen , Fluorine, or Nitrogen. Sulfur is not from these elements, therefore the dipole-dipole force between 2H2S is not a hydrogen bond. Knowing that hydrogen bonds are stronger than dipole-dipole forces, this leads to : water has a higher boiling point than hydrogen sulfide because hydrogen bonds are much stronger than dipole-dipole bonds.
| Mohammad Khachfestudent of best teacher; Manal Abi Saab ArchivesCategories |
RSS Feed