Intermolecular Forces and the States of Matter Solids: The particles of a solid have fixed positions and exhibit motions of vibration. Liquids: The particles of a liquid are free to move within the confines of the liquid. Gas: The particles of a gas are far apart and move randomly and rapidly.

Intermolecular Forces and the States of Matter Melting point: The temperature at which a solid becomes a liquid. Vaporization: The process of a liquid becoming a gas. Boiling point: The temperature at which the particles of a liquid escape and become a gas.

Intermolecular Forces and the States of Matter Condensation: The process by which a gas becomes a liquid. Freezing: The process by which a liquid becomes a solid. This occurs at the freezing point, which is the same as the melting point. Sublimation: When a solid changes directly from the solid to the gaseous state.

Intermolecular Forces and the States of Matter

Intermolecular Forces and the States of Matter Ionic bonds: Ionic bonds are the strongest of forces that hold matter in the condensed states.

Intermolecular Forces and the States of Matter Dipole forces: Polar molecules exist as dipoles. These oppositely charged ends will attract each other.

Intermolecular Forces and the States of Matter Hydrogen bonds: When a hydrogen atom is covalently bonded to a highly electronegative atom like nitrogen, oxygen, or fluorine (N,O,F), it can exhibit an additional polar attraction. This attraction is called a hydrogen bond.

Intermolecular Forces and the States of Matter Dispersion forces: Nonpolar molecules exhibit a dynamic induced dipole, the strength of which increases with molecular weight. The resulting dipole attractions are called dispersion forces or London dispersion forces. © 2013 Pearson Education, Inc.

Intermolecular Forces and the States of Matter Solution: A homogeneous mixture of two or more substances. Solute: A substance that is dispersed in a solution. Solvent: The substance doing the dissolving, usually present in greatest quantity.

Intermolecular Forces and the States of Matter

Intermolecular Forces and the States of Matter “Like dissolves like”: Solutions form most readily when both the solute and solvent have similar intermolecular forces.

Intermolecular Forces and the States of Matter Ionic substances dissolve in water through ion-dipole interactions.

Kinetic Molecular Theory of a Gas The Gas Laws Kinetic Molecular Theory of a Gas Postulates: The particles of a gas are in rapid constant motion. The particles of a gas are tiny compared to the distance between them. There is little attraction between the particles of a gas. Collisions between gas molecules are perfectly elastic. Temperature is a measure of the average kinetic energy of gas molecules.

The Gas Laws

The Gas Laws Boyle’s law: At constant temperature, the volume of a gas is inversely proportional to its pressure. V α 1/P V = a/P PV = a V1P1 = V2P2

The Gas Laws Boyle’s law: At constant temperature, the volume of a gas is inversely proportional to its pressure.

The Gas Laws Boyle’s law: At constant temperature, the volume of a gas is inversely proportional to its pressure.

The Gas Laws Charles’s law: At constant pressure, the volume of a gas is directly proportional to its absolute temperature. V α T V = bT V/T = b V1/T1 = V2/T2

The Gas Laws Charles’s law: At constant pressure, the volume of a gas is directly proportional to its absolute temperature.

The Gas Laws Charles’s Law

The Gas Laws Avogadro’s law: At fixed temperature and pressure, the volume of a gas is directly proportional to the amount of gas. V α n V = cn V/n = c V1/n1 = V2/n2

The Gas Laws Standard temperature and pressure: Standard temperature = 0 oC Standard pressure = 1 atm A mole of any gas at STP occupies 22.4 L

The Gas Laws Combined gas law: P1V1 = P2V2 T1 T2

The Gas Laws Ideal gas law: PV = nRT R = 0.0821