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  2. Ammonium nitrate - Wikipedia

    en.wikipedia.org/wiki/Ammonium_nitrate

    The ammonia required for this process is obtained by the Haber process from nitrogen and hydrogen. Ammonia produced by the Haber process can be oxidized to nitric acid by the Ostwald process. Ammonia is used in its anhydrous form (a gas) and the nitric acid is concentrated. The reaction is violent owing to its highly exothermic nature. After ...

  3. Exothermic process - Wikipedia

    en.wikipedia.org/wiki/Exothermic_process

    Photosynthesis, the process that allows plants to convert carbon dioxide and water to sugar and oxygen, is an endothermic process: plants absorb radiant energy from the sun and use it in an endothermic, otherwise non-spontaneous process. The chemical energy stored can be freed by the inverse (spontaneous) process: combustion of sugar, which ...

  4. Endothermic process - Wikipedia

    en.wikipedia.org/wiki/Endothermic_process

    An endothermic process may be a chemical process, such as dissolving ammonium nitrate (NH 4 NO 3) in water (H 2 O), or a physical process, such as the melting of ice cubes. [5] The opposite of an endothermic process is an exothermic process, one that releases or "gives out" energy, usually in the form of heat and sometimes as electrical energy. [1]

  5. Enthalpy change of solution - Wikipedia

    en.wikipedia.org/wiki/Enthalpy_change_of_solution

    The energy released by the solvation of the ammonium ions and nitrate ions is less than the energy absorbed in breaking up the ammonium nitrate ionic lattice and the attractions between water molecules. Dissolving potassium hydroxide is exothermic, as more energy is released during solvation than is used in breaking up the solute and solvent.

  6. Thermochemical equation - Wikipedia

    en.wikipedia.org/wiki/Thermochemical_equation

    Hess's law states that the sum of the energy changes of all thermochemical equations included in an overall reaction is equal to the overall energy change. Since Δ H {\displaystyle \Delta H} is a state function and is not dependent on how reactants become products as a result, steps (in the form of several thermochemical equations) can be used ...

  7. Endergonic reaction - Wikipedia

    en.wikipedia.org/wiki/Endergonic_reaction

    The activation energy for the reaction is typically larger than the overall energy of the exergonic reaction (1). Endergonic reactions are nonspontaneous. The progress of the reaction is shown by the line. The change of Gibbs free energy (ΔG) during an endergonic reaction is a positive value because energy is gained (2).

  8. Exothermic reaction - Wikipedia

    en.wikipedia.org/wiki/Exothermic_reaction

    An energy profile of an exothermic reaction. In an exothermic reaction, by definition, the enthalpy change has a negative value: ΔH = H products - H reactants < 0. where a larger value (the higher energy of the reactants) is subtracted from a smaller value (the lower energy of the products). For example, when hydrogen burns: 2H 2 (g) + O 2 (g ...

  9. Thermochemistry - Wikipedia

    en.wikipedia.org/wiki/Thermochemistry

    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.