15. Name the types of attractive forces that will contribute to the interactions between atoms, molecules, or ions in the following substances. Indicate the one(s) you expect to predominate.
The attractive forces between this molecule is ionic forces. Since the bond is ionic, ion-ion forces contribute to its interactions.
The forces acting between this molecule dipole-dipole forces. This is because of the covalent bond of the hydrogen iodine. The electrons are mostly in the valence shell of the iodine atom, therefore giving the molecule dipoles.
The only force acting upon this molecule would be London dispersion forces. This would be caused by the proximity of this atom to other atoms and the electrons being shifted within the atom itself. The electronic shift causes quick dipoles. They are quickly resolved, but they still affect the atom's motion.
The force acting upon this molecule would also be London dispersion forces. The molecule is a non-polar diatomic molecule, but it still has the same effect from other molecules.
23. List the following substances in order of increasing normal boiling points Tb, and explain your reasoning: No, NH3, Ne, RbCl.
The lowest normal boiling point would be owned by Ne because it is a noble gas and therefore it does not interact with other molecules and there are no intermolecular forces acting upon it. The next boiling point would be for NO because it is bonded by a covalent bond. The molecule is also relatively non-polar and therefore no intermolecular forces act upon it. The next boiling point would be for NH3. This molecule has dipole forces acting upon it because it is a polar covalent molecule. This makes it harder to separate the molecule through heating. This molecule also has hydrogen bonding forces acting upon it also. That is a weak intermolecular force, but it is acting upon the molecule nonetheless. The highest boiling point belongs to RbCl because it is bonded by an ionic bond, the strongest intermolecular force. It is the most difficult to separate these molecules through heat.