Figure: 2.1 Title: Van der Waals forces are induced-dipole–induced-dipole interactions. Caption: The molecules of an alkane are held together by van der Waals forces.

Figure: 02-01-02UN Title: Boiling points of alkanes. Caption: Differences in the boiling points of several alkanes. Branching decreases the boiling point.

Figure: 02-01-03UN Title: The boiling points of the compounds in any homologous series increase as their molecular weights increase because of the increase in van der Waals forces. The boiling points are also affected by the polar character of the C-Z bond. Caption: The C-Z bond is polar because nitrogen, oxygen, and halogens are more electronegative than the carbon to which they are attached.

Figure: 02-01-04UN Title: The magnitude of the charge differential between the two bonded atoms is indicated by the bond dipole moment. Caption: The dipole moment of a bond is equal to the magnitude of the charge on one of the bonded atoms times the distance between the bonded atoms.

Figure: 02-01-05UN Title: Dipole-dipole interactions. Caption: Molecules with dipole moments are attracted to one another. Dipole-dipole interactions are stronger than London forces in small molecules.

Figure: 02-01-06UN Title: Boiling points of cyclopentane and tetrahydrofuran. Caption: Ethers generally have higher boiling points than alkanes of comparable molecular weight because both van der Waals forces and dipole-dipole interactions must be overcome for an ether to boil.

Figure: 02-01-07UN Title: Hydrogen bonding in water, ammonia, and hydrogen fluoride. Caption: Hydrogen bonds occur between molecules that contain O, N, or F with a hydrogen directly attached to the O, N, or F.

Figure: 02-01-08UN Title: Hydrogen bonding in water. Caption: The hydrogen bond forms between the hydrogen of one water molecule and a nonbonding pair of electrons on the oxygen of the other water molecule.

Figure: 02-01-09UN Title: Boiling points of primary, secondary, and tertiary amines. Caption: For amines with the same molecular weight, a primary amine has a higher boiling point than a secondary amine and a secondary amine has a higher boiling point than a tertiary amine.

Figure: 02-02 Title: Figure 2.2. Melting points of straight-chain alkanes. Caption: Alkanes with even numbers of carbon atoms fall on a melting-point curve that is higher than the melting-point curve for alkanes with odd numbers of carbon atoms.

Figure: 02-02-01UN Title: Alkanes with odd numbers of carbon atoms have weaker intermolecular attractions and corresponding lower melting points. Caption: Alkanes with an odd number of carbons pack less tightly than alkanes with an even number of carbon atoms.

Figure: 02-02-02UN Title: Solvation of a polar compound by water. Caption: The negative poles of the solvent molecules surround the positive poles of the polar solute and the positive poles of the solvent molecules surround the negative poles of the polar solute.