List the most i mportant (strongest) intermolecular force(s) that must be overcome to

(a) vaporize liquid CH 3 OH
(b) remove water of hydration from NiSO 4 • 7H 2 O
(c) melt solid KBr
so for a Isaid H bonding, for b I said ion-dipole (not sure about this one), and c I said ion-ion. Thoughts? Thanks

I would agree with your answers although I usually don't think of ion-ion (ionic bonds) as being an intermolecular force. Most discussions I've seen classify ionic bonds and covalent bonds as so-callee "main bonding types", then add intermolecular forces as dipole-dipole, ion-dipole, dispersion, etc.I see melting KBr crystals as breaking the crystal lattice bonds; however, ionic bonding is what forms that crystal lattice structure. I hope other tutors will weigh in on this.

Your answers are mostly correct! Let's go through each compound to determine the most important intermolecular forces involved.

(a) Vaporizing liquid CH3OH:
To determine the intermolecular force responsible for vaporizing CH3OH (methanol), we need to consider the bonding between molecules. Methanol consists of polar covalent bonds due to the difference in electronegativity between carbon, hydrogen, and oxygen atoms.

The dominant intermolecular force between methanol molecules is hydrogen bonding. Hydrogen bonding occurs when a hydrogen atom is bonded to a highly electronegative atom like oxygen, nitrogen, or fluorine, and forms a weak electrostatic attraction with another electronegative atom.

Therefore, the most important intermolecular force to overcome when vaporizing liquid CH3OH is hydrogen bonding.

(b) Removing water of hydration from NiSO4 • 7H2O:
In this case, we need to consider the removal of water molecules (H2O) from the crystal structure of hydrated nickel sulfate (NiSO4 • 7H2O).

The most influential intermolecular force involved here is the ion-dipole interaction. This occurs between the charged ions present in the NiSO4 compound and the polar water molecules. When water is removed, these ion-dipole interactions must be overcome.

Thus, the most important intermolecular force to overcome when removing water of hydration from NiSO4 • 7H2O is ion-dipole interaction.

(c) Melting solid KBr:
To determine the intermolecular force responsible for melting solid KBr (potassium bromide), we need to analyze the bonding nature of the compound. KBr consists of ionic bonds between potassium cations (K+) and bromide anions (Br-). Ionic bonds are formed by the electrostatic attraction between oppositely charged ions.

The primary intermolecular force involved in this case is the ion-ion interaction, as it requires breaking the strong electrostatic forces between the potassium and bromide ions in the solid lattice.

Therefore, the most important intermolecular force to overcome when melting solid KBr is ion-ion interaction.

Overall, your answers are mostly correct! The important intermolecular forces involved are hydrogen bonding for CH3OH, ion-dipole interaction for removing water of hydration from NiSO4 • 7H2O, and ion-ion interaction for melting solid KBr.