type of intermolecular forces in CH3-OH
Answers
Answer:
Explanation:
Methanol is a polar molecule (1.69 D), and so it exhibits all three of the van der Waals forces: Keesom forces (dipole-dipole attraction), Debye forces (induced attraction) and London dispersion forces (which all molecules exhibit). Because hydrogen is bonded to oxygen, it exhibits hydrogen bonding which accounts for the fact that it is a liquid at room temperature.
More on intermolecular forces
Note: There are three van der Waals forces (Keesom forces, Debye forces and London dispersion forces). Some textbooks and some teachers' dusty old notes erroneously equate van der Waals forces only with London dispersion forces.
1. London dispersion forces .... forces between all molecules. In the past London dispersion forces were characterized as the attraction between temporary dipoles. There may be more to it than that. Dispersion forces are a quantum interaction. All molecules exhibit London dispersion forces, LDF's. The strength of LDF's is proportional to the polarizability of the molecule, which in turn, depends on the number of electrons and the surface area of the molecule. Contrary to what some teachers and even some authors say, in many cases London dispersion forces can be stronger than Keesom or Debye forces and are second only to hydrogen bonding.
2. Keesom forces (dipole-dipole attraction) ... the attraction of one polar molecule for another. Oppositely charged ends of the molecules undergo electrostatic attraction.
3. Debye forces (induced attraction) .... the attraction between a polar molecule and one which is nonpolar, where the polar molecule induces a charge separation in the nonpolar molecule. Debye forces can also exist between two polar molecules, even the same kind of molecule.
4. Hydrogen bonding .... The weakly covalent bonds found between the hydrogen atom of one molecule where it is bonded to N, O or F, and the N, O, or F of an adjacent molecule. The hydrogen atom functions as a bridge, forming a bond between two molecules. Hydrogen bonding is more than an electrostatic attraction between molecules, instead there is evidence of orbital overlap and covalent bond formation.