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  2. Alkylation unit - Wikipedia

    en.wikipedia.org/wiki/Alkylation_unit

    Three CIL alkylation units, each with 300,000 ton-per-year capacity, came online in China in 2019 at Sinopec’s refineries in Jiujiang City, [12] Anqing City, and Wuhan City. [11] As of 2022, there were three such units operated by PetroChina and seven in total, including a converted HF alkylation unit at Sinopec's Wuhan plant. [13]

  3. 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.

  4. Ammonia solution - Wikipedia

    en.wikipedia.org/wiki/Ammonia_solution

    In aqueous solution, ammonia deprotonates a small fraction of the water to give ammonium and hydroxide according to the following equilibrium: . NH 3 + H 2 O ⇌ NH + 4 + OH −.. In a 1 M ammonia solution, about 0.42% of the ammonia is converted to ammonium, equivalent to pH = 11.63 because [NH +

  5. Electron affinity - Wikipedia

    en.wikipedia.org/wiki/Electron_affinity

    The relation between the two is E ea = −ΔE(attach). However, if the value assigned to E ea is negative, the negative sign implies a reversal of direction, and energy is required to attach an electron. In this case, the electron capture is an endothermic process and the relationship, E ea = −ΔE(attach) is still valid. Negative values ...

  6. Neutralization (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Neutralization_(chemistry)

    When a strong acid is neutralized by a strong base there are no excess hydrogen ions left in the solution. The solution is said to be neutral as it is neither acidic nor alkaline. The pH of such a solution is close to a value of 7; the exact pH value is dependent on the temperature of the solution. Neutralization is an exothermic reaction.

  7. Chemical reaction - Wikipedia

    en.wikipedia.org/wiki/Chemical_reaction

    G: free energy, H: enthalpy, T: temperature, S: entropy, Δ: difference (change between original and product) Reactions can be exothermic, where ΔH is negative and energy is released. Typical examples of exothermic reactions are combustion, precipitation and crystallization, in which ordered solids are formed from disordered gaseous or liquid ...

  8. Exothermic reaction - Wikipedia

    en.wikipedia.org/wiki/Exothermic_reaction

    In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." [ 1 ] [ 2 ] Exothermic reactions usually release heat . The term is often confused with exergonic reaction , which IUPAC defines as "... a reaction for which the overall standard Gibbs energy change Δ G ⚬ is negative."

  9. Alkalinity - Wikipedia

    en.wikipedia.org/wiki/Alkalinity

    3 will increase alkalinity by 2 units. Increased dissolution of carbonate rock by acidification from acid rain and mining has contributed to increased alkalinity concentrations in some major rivers throughout the eastern U.S. [ 7 ] The following reaction shows how acid rain, containing sulfuric acid, can have the effect of increasing river ...