Intermolecular Forces

Question 1

What are the types of intermolecular forces? (3)

Answer 1

-London dispersion forces
-dipole-dipole interactions
-hydrogen bonding

Question 2

What are London dispersion forces? (2)

Answer 2

They arise due to temporary fluctuations in electron distribution, creating temporary dipoles. The strength of London dispersion forces increases with increasing molecular size.

Question 3

What are dipole-dipole interactions? (2)

Answer 3

These occur between polar molecules where the positive end of one molecule attracts the negative end of another molecule. Dipole-dipole interactions are stronger than London dispersion forces.

Question 4

What is hydrogen bonding? (1)

Answer 4

A special type of dipole-dipole interaction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom. The hydrogen atom carries a partial positive charge and can form a strong electrostatic interaction with a lone pair of electrons on the electronegative atom of another molecule.

Question 5

What are the most electronegative atoms? (3)

Answer 5

Fluorine
Oxygen
Nitrogen

Question 6

What properties do intermolecular forces impact? (3)

Answer 6

-boiling point
-melting point
-viscosity

Question 7

How do intermolecular forces affect solubility? (

Answer 7

Polar substances tend to dissolve in polar solvents due to favorable dipole-dipole interactions or hydrogen bonding. Nonpolar substances dissolve better in nonpolar solvents due to London dispersion forces.

Question 8

How do intermolecular forces influence molecular structure? (2)

Answer 8

The shape and size of molecules influence the strength of intermolecular forces. Branched or larger molecules typically have stronger London dispersion forces due to increased surface area.

Question 9

What is a key concept of molecular size, in terms of van der waals forces? (1)

Answer 9

Larger molecules have more electrons and experience stronger Van der Waals forces.

Question 10

What is a key concept of shape, in terms of van der waals forces? (1)

Answer 10

Molecules with larger surface areas tend to have stronger Van der Waals forces because they can have more points of contact with neighboring molecules.

Question 11

What is a key concept of solubility, in terms of van der waals forces? (1)

Answer 11

Van der Waals forces influence the solubility of substances in nonpolar solvents.