Chapter 11: States of Matter - Liquids and Solids

Vocabulary flashcards covering key concepts related to states of matter, phase transitions, intermolecular forces, and solid structures.

Change of State (Phase Transition)

Change of a substance from one state (solid, liquid, gas) to another.

Melting

Change of a solid to the liquid state.

Freezing

Change of a liquid to the solid state.

Vaporization

Change of a solid or a liquid to the vapor.

Sublimation

Change of a solid directly to the vapor.

Condensation

Change of a gas to either the liquid or the solid state.

Vapor Pressure

The partial pressure of the vapor over the liquid measured at equilibrium.

Dynamic Equilibrium

A state where, in a closed system, evaporation and condensation occur at the same rate.

Boiling Point

The temperature at which the vapor pressure of a liquid is equal to the pressure on the liquid, usually atmospheric pressure.

Freezing Point

The temperature at which a pure liquid changes to a crystalline solid.

Melting Point

The temperature at which a crystalline solid changes to a liquid.

Heat of Fusion (ΔHfus)

The heat needed to melt a solid, given in kJ/mol.

Heat of Vaporization (ΔHvap)

The heat needed to vaporize a liquid, given in kJ/mol.

Phase Diagram

A graphical way to summarize the conditions under which the various states of a substance are stable.

Triple Point

The point on a phase diagram where all three phases (solid, liquid, gas) coexist in equilibrium.

Critical Temperature

The temperature above which the liquid state of a substance can no longer exist.

Critical Pressure

The pressure required to liquefy a gas at its critical temperature.

Surface Tension

The energy required to increase the surface area of a liquid by a unit amount (J/m2).

Capillary Rise

The phenomenon where a liquid rises in a narrow tube due to its attraction to the tube's surface.

Viscosity

The resistance to flow exhibited by liquids and gases.

Intermolecular Forces

The forces of interaction between molecules.

Dipole-Dipole Force

An attractive force between polar molecules due to the alignment of their positive and negative ends.

London (Dispersion) Forces

Weak attractive forces between molecules resulting from small, instantaneous dipoles due to the varying positions of electrons.

Hydrogen Bonding

A weak attractive force between hydrogen atoms bonded to a highly electronegative atom (F, O, N) and a lone pair of electrons on another electronegative atom.

Molecular Solid

A solid consisting of atoms or molecules held together by intermolecular forces.

Metallic Solid

A solid consisting of positive metal cores held together by metallic bonding (a sea of delocalized electrons).

Ionic Solid

A solid composed of cations and anions held together by ionic bonds (electrical attractions between oppositely charged particles).

Covalent Network Solid

A solid consisting of atoms held together in large chains or networks by covalent bonds.

Crystalline Solid

A solid composed of one or more crystals with a well-defined, ordered structure in three dimensions.

Amorphous Solid

A solid with a disordered structure lacking a well-defined arrangement of basic units.

Crystal Lattice

The geometric arrangement of lattice points in a crystal where each point represents the same location within the basic units.

Unit Cell

The smallest boxlike unit from which a crystal can be constructed by stacking the units in three dimensions.

Simple Cubic Unit Cell

A cubic unit cell with atoms only at the corners.

Body-Centered Cubic Unit Cell

A cubic unit cell with atoms at the corners and one atom in the center of the cell.

Face-Centered Cubic Unit Cell

A cubic unit cell with atoms at the corners and on each face of the cell.

Hexagonal Close-Packed Structure

A crystal structure with close-packed atoms stacked in an ABABABA… sequence.

Cubic Close-Packed Structure

A crystal structure where layers of atoms are arranged in an ABCABC… sequence.

Coordination Number

The number of nearest neighbors surrounding an atom in a crystal structure.

Polymorphic

The ability of a substance to crystallize into more than one different structure.

van der Waals forces

A general term that includes both dipole-dipole forces and London forces.