Chemistry: Atoms First Fifth Edition Chapter 12 Liquids and Solids

Flashcards covering key vocabulary terms related to liquids, solids, crystalline structures, phase changes, and phase diagrams from Chapter 12 of Chemistry: Atoms First Fifth Edition.

Intermolecular forces

Attractive forces that hold particles together in the condensed phases.

Condensed phases

Liquids and solids, where intermolecular forces determine the state of matter.

Surface tension

The amount of energy required to stretch or increase the surface of a liquid by a unit area.

Capillary action

The movement of a liquid up a narrow tube due to cohesive and adhesive forces.

Cohesion

The attraction between like molecules.

Adhesion

The attraction between unlike molecules.

Viscosity

A measure of a fluid’s resistance to flow.

Vaporization

The process by which a molecule at the surface of a liquid escapes to the gas phase.

Vapor pressure

The pressure exerted by the vapor when it is in dynamic equilibrium with its liquid phase.

Dynamic equilibrium

A state where the forward process (e.g., evaporation) and reverse process (e.g., condensation) are occurring at the same rate.

Clausius–Clapeyron equation

An equation that relates the natural log of vapor pressure and the reciprocal of absolute temperature.

Boiling point

The temperature at which the vapor pressure of a liquid equals the external atmospheric pressure.

Melting point

The temperature at which the energies of individual particles in a solid enable them to break free of their fixed positions, leading to a phase change to liquid.

Amorphous solids

Solids that lack a regular three-dimensional arrangement of atoms.

Crystalline solid

A solid that possesses rigid and long-range order, with atoms, molecules, or ions occupying specific positions.

Unit cell

The basic repeating structural unit of a crystalline solid.

Coordination number

The number of atoms surrounding an atom in a crystal lattice, indicating packing tightness.

Simple cubic cell

A basic repeating unit in a crystal lattice where atoms are located only at the corners of the cube.

Body-centered cubic cell (bcc)

A type of cubic unit cell with atoms at each corner and one atom in the center of the cube, having a coordination number of 8.

Face-centered cubic cell (fcc)

A type of cubic unit cell with atoms at each corner and one atom in the center of each face, having a coordination number of 12.

Hexagonal close-packed (hcp) structure

A close-packing arrangement where the third layer of atoms is directly over the first layer (ABA… packing).

Cubic close-packed (ccp) structure

A close-packing arrangement where the third layer of atoms is not directly over the first layer (ABC… packing), corresponding to a face-centered cubic cell.

Ionic crystals

Crystals composed of charged ions held together by Coulombic attraction.

Covalent crystals

Crystals where atoms are held together in an extensive three-dimensional network entirely by covalent bonds.

Molecular crystals

Crystals where lattice points are occupied by molecules, with attractive forces being van der Waals forces and/or hydrogen bonding.

Metallic crystals

Crystals where every lattice point is occupied by an atom of the same metal, and electrons are delocalized over the entire crystal.

Phase

A homogeneous part of a system that is separated from the rest of the system by a well-defined boundary.

Phase change

When a substance transforms from one physical state to another (e.g., solid to liquid).

Molar heat of vaporization

The amount of heat required to vaporize one mole of a substance at its boiling point.

Critical temperature

The temperature above which a gas cannot be liquefied, regardless of pressure.

Critical pressure

The minimum pressure that must be applied to liquefy a substance at its critical temperature.

Freezing point (Melting point)

The temperature at which the solid and liquid phases of a substance coexist in equilibrium.

Molar heat of fusion

The energy required to melt one mole of a solid at its melting point.

Sublimation

The process by which molecules go directly from the solid phase to the vapor phase.

Deposition

The reverse process of sublimation, where molecules go directly from the vapor phase to the solid phase.

Molar enthalpy of sublimation

The energy required to sublime one mole of a solid.

Phase diagram

A diagram that summarizes the conditions (pressure and temperature) at which a substance exists as a solid, liquid, or gas.

Triple point

The only specific combination of pressure and temperature where three phases of a substance (solid, liquid, and gas) exist in equilibrium.