Chapter 10: Liquids and Solids Flashcards

Vocabulary practice flashcards covering intermolecular forces, properties of liquids, phase transitions, phase diagrams, types of solids, and lattice structures.

Intermolecular Forces (IMFs)

The various forces of attraction that may exist between the atoms and molecules of a substance as a result of electrostatic phenomena.

Intramolecular Forces

The forces that hold atoms together within a single molecule, such as covalent or ionic bonds.

Dispersion Forces

Weak electrostatic forces of attraction present in all polar and nonpolar substances, caused by temporary instantaneous dipoles and induced dipoles.

Polarizability

The measure of how easily or difficult it is for an external electrostatic charge to distort a molecule's or atom's electron cloud distribution.

Dipole-Dipole Attractions

Electrostatic attractions between the partial positive end of one polar molecule and the partial negative end of another polar molecule.

Hydrogen Bonding

An unusually strong type of dipole-dipole attraction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom ($N$, $O$, or $F$).

Viscosity

A measure of a liquid's resistance to flow.

Cohesive Forces

The intermolecular forces of attraction between identical molecules within a substance.

Adhesive Forces

The intermolecular forces of attraction between molecules of different chemical identities, such as between a liquid and a solid container wall.

Surface Tension

The energy required to increase the surface area of a liquid, or the force that causes a liquid surface to behave like a stretched elastic membrane.

Capillary Action

The process in which a liquid flows within a porous material or narrow tube due to the relative strengths of adhesive and cohesive forces.

Dynamic Equilibrium

A state in a closed system where the rate of a forward process (such as vaporization) equals the rate of the reverse process (such as condensation).

Vapor Pressure

The pressure exerted by a vapor in dynamic equilibrium with its liquid phase in a closed container at a specified temperature.

Normal Boiling Point

The temperature at which a liquid's equilibrium vapor pressure equals $1\,\text{atm}$ ($101.3\,\text{kPa}$).

Clausius-Clapeyron Equation

An equation relating a substance's vapor pressure and temperature: $\ln\left(\frac{P_2}{P_1}\right) = -\frac{\Delta H_{\text{vap}}}{R} \left(\frac{1}{T_2} - \frac{1}{T_1}\right)$, where $R = 8.31\,\text{J\,mol}^{-1}\text{K}^{-1}$ and temperatures are in Kelvin.

Enthalpy of Fusion ($\Delta H_{\text{fus}}$)

The energy required to change a given quantity of a substance from the solid state to the liquid state at constant pressure.

Enthalpy of Vaporization ($\Delta H_{\text{vap}}$)

The energy required to change a given quantity of a substance from the liquid state to the gaseous state at constant pressure.

Enthalpy of Sublimation ($\Delta H_{\text{sub}}$)

The energy required to convert a given quantity of a substance directly from the solid state to the gaseous state, approximately equal to $\Delta H_{\text{fus}} + \Delta H_{\text{vap}}$.

Phase Diagram

A graphical representation showing the physical states of a substance at various temperatures and pressures, including transition boundaries between phases.

Triple Point

The unique temperature and pressure at which the solid, liquid, and gas phases of a substance coexist together in dynamic equilibrium.

Critical Point

The specific temperature and pressure above which distinct liquid and gas phases cease to exist.

Supercritical Fluid (SCF)

A state of matter formed above a substance's critical temperature and critical pressure that exhibits physical properties intermediate between liquids and gases.

Crystalline Solid

A solid in which the constituent atoms, ions, or molecules are arranged in a regular, repeating three-dimensional pattern.

Amorphous Solid

A solid whose constituent entities lack a long-range ordered or repeating internal structural arrangement.

Ionic Solid

A crystalline solid composed of positive and negative ions bound together by strong electrostatic ionic attractions (e.g., $\text{NaCl}$).

Metallic Solid

A crystalline solid consisting of metal cations distributed in a delocalized sea of valence electrons (e.g., copper).

Covalent Network Solid

A crystalline solid composed of atoms interconnected throughout a three-dimensional network by strong covalent bonds (e.g., diamond, $\text{SiO}_2$).

Molecular Solid

A crystalline solid composed of neutral molecules held together by relatively weak intermolecular forces (e.g., solid $\text{CO}_2$, $\text{I}_2$).

Crystal Defects

Irregularities or disruptions in the ideal repeating lattice structure of a crystalline solid, including vacancies, interstitial impurities, and substitutional impurities.

Unit Cell

The smallest structural repeating unit of a crystal lattice that generates the entire crystal lattice when repeated in three dimensions.

Coordination Number

The number of adjacent atoms, ions, or molecules that directly touch a central particle in a crystal lattice structure.

Simple Cubic Structure

A crystalline lattice with particles located only at the eight corners of a unit cell, giving a net count of $1$ atom per unit cell and a coordination number of $6$.

Body-Centered Cubic (BCC) Structure

A crystalline unit cell containing particles at eight corners and one particle in the center, giving a net count of $2$ atoms per unit cell and a coordination number of $8$.

Face-Centered Cubic (FCC) Structure

A crystalline unit cell containing particles at eight corners and six face centers, giving a net count of $4$ atoms per unit cell and a coordination number of $12$.

Cubic Closest Packing (CCP)

A close-packed crystal structure formed by three alternating layers ($ABCABC\dots$) of hexagonally arranged spheres, equivalent in geometry to a face-centered cubic structure.

Hexagonal Closest Packing (HCP)

A close-packed crystal structure formed by two alternating layers ($ABABAB\dots$) of hexagonally arranged spheres.

X-ray Diffraction

An analytical method used to determine crystal structures and interatomic distances by measuring the scattering pattern of X-rays passing through a crystalline material.