Study of the heat energy associated with chemical reactions and/or physical transformations
For other uses, see chemical thermodynamics.
Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction may release or absorb energy, and a phase change may do the same. Thermochemistry focuses on the energy exchange between a system and its surroundings in the form of heat. Thermochemistry is useful in predicting reactant and product quantities throughout the course of a given reaction. In combination with entropy determinations, it is also used to predict whether a reaction is spontaneous or non-spontaneous, favorable or unfavorable.
Endothermic reactions absorb heat, while exothermic reactions release heat. Thermochemistry coalesces the concepts of thermodynamics with the concept of energy in the form of chemical bonds. The subject commonly includes calculations of such quantities as heat capacity, heat of combustion, heat of formation, enthalpy, entropy, and free energy.
The world's first ice-calorimeter, used in the winter of 1782–83, by Antoine Lavoisier and Pierre-Simon Laplace, to determine the heat evolved in various chemical changes; calculations which were based on Joseph Black's prior discovery of latent heat. These experiments mark the foundation of thermochemistry.
Thermochemistry is one part of the broader field of chemical thermodynamics, which deals with the exchange of all forms of energy between system and surroundings, including not only heat but also various forms of work, as well the exchange of matter. When all forms of energy are considered, the concepts of exothermic and endothermic reactions are generalized to exergonic reactions and endergonic reactions.
Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction...
Adenosine triphosphate (ATP) is a nucleotide that provides energy to drive and support many processes in living cells, such as muscle contraction, nerve...
laws, Kirchhoff's law of thermal radiation, and Kirchhoff's law of thermochemistry. The Bunsen–Kirchhoff Award for spectroscopy is named after Kirchhoff...
solid–gas interfaces, solid–vacuum interfaces, and liquid-gas interfaces. Thermochemistry –The branch of chemistry that studies the relation between chemical...
which the standard Gibbs free energy of formation can be calculated. Thermochemistry Calorimetry M. W. Chase, NIST – JANAF Thermochemical Tables, 4th Edition...
exchange. Intended for main group thermochemistry and non-covalent interactions, transition metal thermochemistry and organometallics. It is usually...
chemist and doctor who formulated Hess' law, an early principle of thermochemistry. Hess was born on 7 August 1802 in Geneva, France (Switzerland after...
Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide, in various ratios. The gas often contains some carbon dioxide and methane. It is...
Hexagonal Point group C2v Molecular shape Bent Dipole moment 1.8546 D Thermochemistry Heat capacity (C) 75.385 ± 0.05 J/(mol·K) Std molar entropy (S⦵298)...
on 22 April 2017. Retrieved 1 October 2017. Sato, Motoaki (1990). "Thermochemistry of the formation of fossil fuels". Fluid-Mineral Interactions: A Tribute...
In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." Exothermic reactions usually...
Benson who spent a career developing the concept.[page needed] The thermochemistry of reactive intermediates—carbocations, carbanions, and radicals—is...
substance. For example, the Gibbs free energy of a compound in the area of thermochemistry is often quantified in units of kilojoules per mole (symbol: kJ·mol−1...
equivalence between calories and joules has varied over the years, but in thermochemistry and nutrition it is now generally assumed that one (small) calorie...
Point group C3v Molecular shape Trigonal pyramid Dipole moment 1.42 D Thermochemistry Std molar entropy (S⦵298) 193 J/(mol·K) Std enthalpy of formation (ΔfH⦵298)...
heat changes using the calorimeter, a subject which became known as thermochemistry. The development of the steam engine focused attention on calorimetry...
surface. A particularly important objective, called computational thermochemistry, is to calculate thermochemical quantities such as the enthalpy of...
degree, from a temperature of 14.5 °C, at a pressure of 1 atm. For thermochemistry a calorie of 4.184 J is used, but other calories have also been defined...
surroundings during change of phase or chemical reaction taking place called thermochemistry Study of colligative properties of number of species present in solution...
ISBN 079234538X. Hopkins, Harry P.; Wulff, Claus A. (1965). "The solution thermochemistry of polyvalent electrolytes. I. Calcium hydroxide". The Journal of Physical...
be a radical addition reaction. Breazeale, J. D.; MacLaren, R. O.. Thermochemistry of oxygen-fluorine bonding, United Technology Center, Sunnyvale, CA...
"Fossil fuels". Geological Survey Ireland. Retrieved 29 October 2021. "thermochemistry of fossil fuel formation" (PDF). Archived (PDF) from the original on...
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