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  2. Acid dissociation constant - Wikipedia

    en.wikipedia.org/wiki/Acid_dissociation_constant

    Free energy is made up of an enthalpy term and an entropy term. [11] = The standard enthalpy change can be determined by calorimetry or by using the van 't Hoff equation, though the calorimetric method is preferable. When both the standard enthalpy change and acid dissociation constant have been determined, the standard entropy change is easily ...

  3. Polyelectrolyte - Wikipedia

    en.wikipedia.org/wiki/Polyelectrolyte

    Similarly, polyelectrolytes can be divided into "weak" and "strong" types. A "strong" polyelectrolyte dissociates completely in solution for most reasonable pH values. A "weak" polyelectrolyte, by contrast, has a dissociation constant (pKa or pKb) in the range of ~2 to ~10, meaning that it will be partially dissociated at intermediate pH. Thus ...

  4. Contact activation system - Wikipedia

    en.wikipedia.org/wiki/Contact_activation_system

    PKa's cleavage of HK liberates BK and promotes inflammation. FXIIa's cleavage of FXI initiates coagulation. In the contact activation system or CAS , three proteins in the blood, factor XII (FXII), prekallikrein (PK) and high molecular weight kininogen (HK), bind to a surface and cause blood coagulation and inflammation .

  5. Proton affinity - Wikipedia

    en.wikipedia.org/wiki/Proton_affinity

    The higher the proton affinity, the stronger the base and the weaker the conjugate acid in the gas phase.The (reportedly) strongest known base is the ortho-diethynylbenzene dianion (E pa = 1843 kJ/mol), [3] followed by the methanide anion (E pa = 1743 kJ/mol) and the hydride ion (E pa = 1675 kJ/mol), [4] making methane the weakest proton acid [5] in the gas phase, followed by dihydrogen.

  6. PKA (irradiation) - Wikipedia

    en.wikipedia.org/wiki/PKA_(irradiation)

    Atoms can only be displaced if, upon bombardment, the energy they receive exceeds a threshold energy E d. Likewise, when a moving atom collides with a stationary atom, both atoms will have energy greater than E d after the collision only if the original moving atom had an energy exceeding 2E d.

  7. Negative energy - Wikipedia

    en.wikipedia.org/wiki/Negative_energy

    The negative-energy particle then crosses the event horizon into the black hole, with the law of conservation of energy requiring that an equal amount of positive energy should escape. In the Penrose process , a body divides in two, with one half gaining negative energy and falling in, while the other half gains an equal amount of positive ...

  8. Electron affinity - Wikipedia

    en.wikipedia.org/wiki/Electron_affinity

    The electron affinity (E ea) of an atom or molecule is defined as the amount of energy released when an electron attaches to a neutral atom or molecule in the gaseous state to form an anion. X(g) + e − → X − (g) + energy. This differs by sign from the energy change of electron capture ionization. [1]

  9. Debye–Hückel theory - Wikipedia

    en.wikipedia.org/wiki/Debye–Hückel_theory

    The Debye–Hückel theory was proposed by Peter Debye and Erich Hückel as a theoretical explanation for departures from ideality in solutions of electrolytes and plasmas. [1] It is a linearized Poisson–Boltzmann model, which assumes an extremely simplified model of electrolyte solution but nevertheless gave accurate predictions of mean activity coefficients for ions in dilute solution.