IMF Notes 2018.docx

What are the three types of intermolecular forces?

Hydrogen bonding, dipole-dipole forces, and dispersion forces.

What is the key characteristic of dispersion forces?

They are present between all molecules and arise from temporary dipoles due to random movement of electrons.

How do dispersion forces vary with molecular size?

Dispersion forces become stronger with an increase in the number of electrons and with a more linear shape of the molecule.

What defines dipole-dipole forces?

Attractions between the partially charged ends of polar molecules.

Why are dipole-dipole forces generally stronger than dispersion forces?

Dipole-dipole forces result from permanent dipoles formed by significant differences in electronegativity between bonded atoms.

What type of molecules exhibit hydrogen bonding?

Molecules containing H-F, H-N, or H-O covalent bonds.

Which intermolecular force is the strongest?

Hydrogen bonding.

What is an ion-dipole force?

An attractive force between an ion and a neutral polar molecule due to electrostatic attraction.

How do dispersion forces affect boiling points in noble gases?

Boiling points increase with atomic size due to increased dispersion forces from more electrons.

What effect does molecular shape have on dispersion forces?

More linear shapes result in stronger dispersion forces compared to branched or clustered shapes.

Give an example of a substance that primarily exhibits dispersion forces.

Chlorine (Cl2).

Provide an example of a substance that exhibits dipole-dipole forces.

Hydrogen Chloride (HCl).

What is the relationship between electronegativity difference and dipole-dipole force strength?

As electronegativity difference increases, the strength of the dipole-dipole force increases.

What is a temporary dipole?

A temporary separation of charge in a molecule due to the random movement of electrons.

What determines the strength of ion-dipole forces?

The strength increases with either the charge on the ion or the magnitude of the dipole of the polar molecule.