Chapter 12: Intermolecular Forces: Liquids, Solids and Phase Changes.

It is any physically distinct homogeneous part of a system, a physical state of matter

electrostatic forces among particles are called intermolecular forces.

Changes from one phase to another of a substance.

The process by which a gas changes into a liquid

The process by which a liquid changes into a gas.

When liquid solidifies the process due to cooling

When solid changes into a liquid due to increase in temperature.

When a solid turns into a gas directly without changing into a liquid first.

When a gas goes directly into a solid phase due to temperature changes.

It is a curve which shows the changes that occur when heat is added to or removed from a particular sample of matter at a a constant rate.

When a system is going from one phase to a second at the same rate as its reverse process, the system is said to be in dynamic equilibrium.

The pressure exerted by a liquid at equilibrium is called its vapor pressure.

It is the temperature at which the vapor pressure equals the external pressure on a system.

The dynamic equilibrium between the change from a solid to a liquid state is called the melting point. It is the same as freezing point.

Phase diagram is a contruct which describes the changes of phase of a substance under various conditions of temperature and pressure.

The liquid-gas line ends at the critical point.

The three phase-transition curves meet at the triple point, the temperature and pressure at which the threee phases of a substance are in equilibrium.

It is half the closest distance between two molecules that come close due to the intermolecular forces between them.

When an ion and a nearby polar molecule or dipole attract each other an ion dipole force results.

When polar molecules lie near each other (in liquids and solids), their partial charges give rise to dipole-dipole forces.

It is a special type of dipole-dipole force that arises from a H-atom bonded to a small, highly electronegative atom with lone pairs (such as O, N, F and rarely in P, S and Cl).

When the electron cloud of a particle can be distorted due to the presence of a charge or a dipole, the particle is said to be polarizable. The ease with which this can happen is called polarizability.

Polarizability increases down a group as atomic size increase. It decreases from left to right across a period as atomic size decreases. Cations are less polarizable than their parent atoms because they are smaller. Anions are more polarizable than their parent atoms, because they are larger.

The intermolecular force responsible for the condensed states of nonpolar substances is called the London dispersion force. They are also understood as induced dipole-induced dipole interactions.

This is the energy required to increase the surface area of a liquid by a unit amount.

The rising of a liquid through a narrow channel against the pull of gravity is called capillarity.

It is a liquid's resistance to its flow resulting from intermolecular attractions that impede its movement. Heating reduces viscosity.

It has great solvent power due to the presence of H-bonds. It has high specific heat capacity. It has high surface tension and capillarity due to the presence of H-bonds. The density of water in its solid state is less than that of its density in liquid state.