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energy : capacity to supply heat or do work | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
enthalpy (H) : sum of a systemâs internal energy and the mathematical product of its pressure and volume | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
enthalpy change (ÎH) : heat released or absorbed by a system under constant pressure during a chemical or physical process | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
exothermic process : chemical reaction or physical change that releases heat | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
expansion work (pressure-volume work) : work done as a system expands or contracts against external pressure | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
first law of thermodynamics : internal energy of a system changes due to heat flow in or out of the system or work done on or by the system | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
heat (q) : transfer of thermal energy between two bodies | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
heat capacity (C) : extensive property of a body of matter that represents the quantity of heat required to increase its temperature by 1 degree Celsius (or 1 kelvin) | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
Hessâs law : if a process can be represented as the sum of several steps, the enthalpy change of the process equals the sum of the enthalpy changes of the steps | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
hydrocarbon : compound composed only of hydrogen and carbon; the major component of fossil fuels | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
internal energy (U) : total of all possible kinds of energy present in a substance or substances | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
joule (J) : SI unit of energy; amount of energy used when a force of 1 newton moves an object 1 meter, 1 J = 1 kg m2/s2and 4.184 J = 1 cal | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
kinetic energy : energy associated with an object's motion, equal to one-half the product of the object's mass and the square of its velocity,12mv212mv2(wherem= mass andv= velocity) | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
lattice energy (ÎHlattice) : energy required to separate one mole of an ionic solid into its component gaseous ions | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
nutritional calorie (Calorie) : unit used for quantifying energy provided by digestion of foods, defined as 1000 cal or 1 kcal | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
potential energy : energy of a particle or system of particles derived from relative position, composition, or condition | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
specific heat capacity (c) : intensive property of a substance that represents the quantity of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius (or 1 kelvin) | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
standard enthalpy of combustion(ÎHc°)(ÎHc°) : heat released when one mole of a compound undergoes complete combustion under standard conditions | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
standard enthalpy of formation(ÎHf°)(ÎHf°) : enthalpy change of a chemical reaction in which 1 mole of a pure substance is formed from its elements in their most stable states under standard state conditions | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
standard state : set of physical conditions as accepted as common reference conditions for reporting thermodynamic properties; 1 bar of pressure, and solutions at 1 molar concentrations, usually at a temperature of 298.15 K | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
state function : property depending only on the state of a system, and not the path taken to reach that state | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
surroundings : all matter other than the system being studied | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
system : portion of matter undergoing a chemical or physical change being studied | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
temperature : intensive property of matter that is a quantitative measure of âhotnessâ and âcoldnessâ | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
thermal energy : kinetic energy associated with the random motion of atoms and molecules | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
thermochemistry : study of measuring the amount of heat absorbed or released during a chemical reaction or a physical change | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
work (w) : energy transfer due to changes in external, macroscopic variables such as pressure and volume; or causing matter to move against an opposing force | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-key-terms |
Energy is the capacity to supply heat or do work (applying a force to move matter). Kinetic energy (KE) is the energy of motion; potential energy is energy due to relative position, composition, or condition. When energy is converted from one form into another, energy is neither created nor destroyed (law of conservati... | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
The thermal energy of matter is due to the kinetic energies of its constituent atoms or molecules. Temperature is an intensive property of matter reflecting hotness or coldness that increases as the average kinetic energy increases. Heat is the transfer of thermal energy between objects at different temperatures. Chemi... | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
Specific heat and heat capacity are measures of the energy needed to change the temperature of a substance or object. The amount of heat absorbed or released by a substance depends directly on the type of substance, its mass, and the temperature change it undergoes. | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
Calorimetry is used to measure the amount of thermal energy transferred in a chemical or physical process. This requires careful measurement of the temperature change that occurs during the process and the masses of the system and surroundings. These measured quantities are then used to compute the amount of heat produ... | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
Calorimeters are designed to minimize energy exchange between their contents and the external environment. They range from simple coffee cup calorimeters used by introductory chemistry students to sophisticated bomb calorimeters used to determine the energy content of food. | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
If a chemical change is carried out at constant pressure and the only work done is caused by expansion or contraction,qfor the change is called the enthalpy change with the symbol ÎH, orÎH°ÎH°for reactions occurring under standard state conditions at 298 K. The value of ÎHfor a reaction in one direction is equal ... | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
The strength of a covalent bond is measured by its bond dissociation energy, that is, the amount of energy required to break that particular bond in a mole of molecules. Multiple bonds are stronger than single bonds between the same atoms. The enthalpy of a reaction can be estimated based on the energy input required t... | https://openstax.org/books/chemistry-atoms-first-2e/pages/9-summary |
h = 2 T cos θ r Ï g h = 2 T cos θ r Ï g | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-equations |
P = A e â Î H vap / R T P = A e â Î H vap / R T | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-equations |
ln P = â Î H vap R T + ln A ln P = â Î H vap R T + ln A | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-equations |
ln ( P 2 P 1 ) = Î H vap R ( 1 T 1 â 1 T 2 ) ln ( P 2 P 1 ) = Î H vap R ( 1 T 1 â 1 T 2 ) | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-equations |
n λ = 2 d sin θ n λ = 2 d sin θ | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-equations |
adhesive force : force of attraction between molecules of different chemical identities | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
amorphous solid : (also, noncrystalline solid) solid in which the particles lack an ordered internal structure | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
body-centered cubic (BCC) solid : crystalline structure that has a cubic unit cell with lattice points at the corners and in the center of the cell | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
body-centered cubic unit cell : simplest repeating unit of a body-centered cubic crystal; it is a cube containing lattice points at each corner and in the center of the cube | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
boiling point : temperature at which the vapor pressure of a liquid equals the pressure of the gas above it | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
Bragg equation : equation that relates the angles at which X-rays are diffracted by the atoms within a crystal | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
capillary action : flow of liquid within a porous material due to the attraction of the liquid molecules to the surface of the material and to other liquid molecules | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
Clausius-Clapeyron equation : mathematical relationship between the temperature, vapor pressure, and enthalpy of vaporization for a substance | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
cohesive force : force of attraction between identical molecules | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
condensation : change from a gaseous to a liquid state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
coordination number : number of atoms closest to any given atom in a crystal or to the central metal atom in a complex | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
covalent network solid : solid whose particles are held together by covalent bonds | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
critical point : temperature and pressure above which a gas cannot be condensed into a liquid | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
crystalline solid : solid in which the particles are arranged in a definite repeating pattern | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
cubic closest packing (CCP) : crystalline structure in which planes of closely packed atoms or ions are stacked as a series of three alternating layers of different relative orientations (ABC) | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
deposition : change from a gaseous state directly to a solid state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
diffraction : redirection of electromagnetic radiation that occurs when it encounters a physical barrier of appropriate dimensions | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
dipole-dipole attraction : intermolecular attraction between two permanent dipoles | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
dispersion force : (also, London dispersion force) attraction between two rapidly fluctuating, temporary dipoles; significant only when particles are very close together | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
dynamic equilibrium : state of a system in which reciprocal processes are occurring at equal rates | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
face-centered cubic (FCC) solid : crystalline structure consisting of a cubic unit cell with lattice points on the corners and in the center of each face | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
face-centered cubic unit cell : simplest repeating unit of a face-centered cubic crystal; it is a cube containing lattice points at each corner and in the center of each face | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
freezing : change from a liquid state to a solid state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
freezing point : temperature at which the solid and liquid phases of a substance are in equilibrium; see alsomelting point | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
hexagonal closest packing (HCP) : crystalline structure in which close packed layers of atoms or ions are stacked as a series of two alternating layers of different relative orientations (AB) | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
hole : (also, interstice) space between atoms within a crystal | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
hydrogen bonding : occurs when exceptionally strong dipoles attract; bonding that exists when hydrogen is bonded to one of the three most electronegative elements: F, O, or N | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
induced dipole : temporary dipole formed when the electrons of an atom or molecule are distorted by the instantaneous dipole of a neighboring atom or molecule | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
instantaneous dipole : temporary dipole that occurs for a brief moment in time when the electrons of an atom or molecule are distributed asymmetrically | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
intermolecular force : noncovalent attractive force between atoms, molecules, and/or ions | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
interstitial sites : spaces between the regular particle positions in any array of atoms or ions | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
ionic solid : solid composed of positive and negative ions held together by strong electrostatic attractions | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
isomorphous : possessing the same crystalline structure | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
melting : change from a solid state to a liquid state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
melting point : temperature at which the solid and liquid phases of a substance are in equilibrium; see alsofreezing point | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
metallic solid : solid composed of metal atoms | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
molecular solid : solid composed of neutral molecules held together by intermolecular forces of attraction | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
normal boiling point : temperature at which a liquidâs vapor pressure equals 1 atm (760 torr) | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
octahedral hole : open space in a crystal at the center of six particles located at the corners of an octahedron | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
phase diagram : pressure-temperature graph summarizing conditions under which the phases of a substance can exist | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
polarizability : measure of the ability of a charge to distort a moleculeâs charge distribution (electron cloud) | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
simple cubic structure : crystalline structure with a cubic unit cell with lattice points only at the corners | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
simple cubic unit cell : (also, primitive cubic unit cell) unit cell in the simple cubic structure | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
space lattice : all points within a crystal that have identical environments | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
sublimation : change from solid state directly to gaseous state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
supercritical fluid : substance at a temperature and pressure higher than its critical point; exhibits properties intermediate between those of gaseous and liquid states | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
surface tension : energy required to increase the area, or length, of a liquid surface by a given amount | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
tetrahedral hole : tetrahedral space formed by four atoms or ions in a crystal | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
triple point : temperature and pressure at which three phases of a substance are in equilibrium | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
unit cell : smallest portion of a space lattice that is repeated in three dimensions to form the entire lattice | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
vacancy : defect that occurs when a position that should contain an atom or ion is vacant | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
van der Waals force : attractive or repulsive force between molecules, including dipole-dipole, dipole-induced dipole, and London dispersion forces; does not include forces due to covalent or ionic bonding, or the attraction between ions and molecules | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
vapor pressure : (also, equilibrium vapor pressure) pressure exerted by a vapor in equilibrium with a solid or a liquid at a given temperature | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
vaporization : change from liquid state to gaseous state | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
viscosity : measure of a liquidâs resistance to flow | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
X-ray crystallography : experimental technique for determining distances between atoms in a crystal by measuring the angles at which X-rays are diffracted when passing through the crystal | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-key-terms |
The physical properties of condensed matter (liquids and solids) can be explained in terms of the kinetic molecular theory. In a liquid, intermolecular attractive forces hold the molecules in contact, although they still have sufficient KE to move past each other. | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-summary |
Intermolecular attractive forces, collectively referred to as van der Waals forces, are responsible for the behavior of liquids and solids and are electrostatic in nature. Dipole-dipole attractions result from the electrostatic attraction of the partial negative end of one polar molecule for the partial positive end of... | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-summary |
The intermolecular forces between molecules in the liquid state vary depending upon their chemical identities and result in corresponding variations in various physical properties. Cohesive forces between like molecules are responsible for a liquidâs viscosity (resistance to flow) and surface tension (elasticity of a... | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-summary |
Phase transitions are processes that convert matter from one physical state into another. There are six phase transitions between the three phases of matter. Melting, vaporization, and sublimation are all endothermic processes, requiring an input of heat to overcome intermolecular attractions. The reciprocal transition... | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-summary |
The temperature and pressure conditions at which a substance exists in solid, liquid, and gaseous states are summarized in a phase diagram for that substance. Phase diagrams are combined plots of pressure-temperature equilibrium curves representing the relationships between phase transition temperatures and pressures. ... | https://openstax.org/books/chemistry-atoms-first-2e/pages/10-summary |
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