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  2. Chemical energy - Wikipedia

    en.wikipedia.org/wiki/Chemical_energy

    Chemical energy is the energy of chemical substances that is released when the substances undergo a chemical reaction and transform into other substances. Some examples of storage media of chemical energy include batteries, [1] food, and gasoline (as well as oxygen gas, which is of high chemical energy due to its relatively weak double bond [2] and indispensable for chemical-energy release in ...

  3. Chemical reaction - Wikipedia

    en.wikipedia.org/wiki/Chemical_reaction

    Higher activation energy implies that the reactants need more energy to start than a reaction with lower activation energy. Temperature, which hastens reactions if raised, since higher temperature increases the energy of the molecules, creating more collisions per unit of time, The presence or absence of a catalyst.

  4. Activated complex - Wikipedia

    en.wikipedia.org/wiki/Activated_complex

    The transition state, represented by the double dagger symbol represents the exact configuration of atoms that has an equal probability of forming either the reactants or products of the given reaction. [5] The activation energy is the minimum amount of energy to initiate a chemical reaction and form the activated complex. [6]

  5. Reaction mechanism - Wikipedia

    en.wikipedia.org/wiki/Reaction_mechanism

    Reaction intermediates are often confused with the transition state. The transition state is a fleeting, high-energy configuration that exists only at the peak of the energy barrier during a reaction, while a reaction intermediate is a relatively stable species that exists for a measurable time between steps in a reaction. Unlike the transition ...

  6. Activation energy - Wikipedia

    en.wikipedia.org/wiki/Activation_energy

    In the Arrhenius model of reaction rates, activation energy is the minimum amount of energy that must be available to reactants for a chemical reaction to occur. [1] The activation energy ( E a ) of a reaction is measured in kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol). [ 2 ]

  7. Chemical thermodynamics - Wikipedia

    en.wikipedia.org/wiki/Chemical_thermodynamics

    Chemical energy is the energy that can be released when chemical substances undergo a transformation through a chemical reaction. Breaking and making chemical bonds involves energy release or uptake, often as heat that may be either absorbed by or evolved from the chemical system.

  8. Transition state theory - Wikipedia

    en.wikipedia.org/wiki/Transition_state_theory

    The free energy of activation, ΔG ‡, is defined in transition state theory to be the energy such that ‡ = ⁡ ‡ ′ holds. The parameters ΔH ‡ and ΔS ‡ can then be inferred by determining ΔG ‡ = ΔH ‡ – TΔS ‡ at different temperatures.

  9. Standard enthalpy of reaction - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_reaction

    Such thermal energy manifests itself, however, in changes in the non-chemical state variables (such as temperature, pressure, volume) of the joint systems, as well as the changes in the mole numbers of the chemical constituents that describe the chemical reaction. [citation needed] Internal energy is defined with respect to some standard state.