thermochemistry
(noun)
 The study of the energy and heat associated with chemical reactions and/or physical transformations.
Examples of thermochemistry in the following topics:
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Standard States and Standard Enthalpy Changes- Graphite is the most stable state of carbon and is used in thermochemistry to define the heat of formation of carbon compounds.
 
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Heat and Work- Scientists and engineers have been able to exploit the principles of thermochemistry to develop technologies ranging from hot/cold packs to gasoline powered combustion engines.
 
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Calorimetry- These experiments mark the foundation of thermochemistry.
 
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Allotropes of Carbon- Graphite is the most stable form of carbon under standard conditions and is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.