Answer to Question #188915 in General Chemistry for Anisa Tamaivena

Question

State the strongest intermolecular force that exists between molecules of the following substances:                    

i)  I2

ii) H2O

iii) CH3Br

iv) HCl

Answer 1

1.) Iodine consists of I2 molecules, and the only attractions between the molecules are van der Waals dispersion forces. There are enough electrons in the I2 molecule to make the temporary dipoles creating the dispersion forces strong enough to hold the iodine together as a solid.

2.) London dispersion forces, under the category of van der Waal forces: These are the weakest of the intermolecular forces and exist between all types of molecules, whether ionic or covalent—polar or nonpolar.

3.) CH3Br is a polar molecule. Dispersion forces (present in all matter) and dipole-dipole forces will be present.

4.) HCl molecules, for example, have a dipole moment because the hydrogen atom has a slight positive charge and the chlorine atom has a slight negative charge. Because of the force of attraction between oppositely charged particles, there is a small dipole-dipole force of attraction between adjacent HCl molecules.