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  2. Pitzer equations - Wikipedia

    en.wikipedia.org/wiki/Pitzer_equations

    They can be used to calculate mixed ion activity coefficients and water activities in solutions of high ionic strength for which the Debye–Hückel theory is no longer adequate. They are more rigorous than the equations of specific ion interaction theory (SIT theory), but Pitzer parameters are more difficult to determine experimentally than ...

  3. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    The bond angle for water is 104.5°. Valence shell electron pair repulsion (VSEPR) theory (/ ˈ v ɛ s p ər, v ə ˈ s ɛ p ər / VESP-ər, [1]: 410 və-SEP-ər [2]) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. [3]

  4. Bond-dissociation energy - Wikipedia

    en.wikipedia.org/wiki/Bond-dissociation_energy

    The term bond-dissociation energy is similar to the related notion of bond-dissociation enthalpy (or bond enthalpy), which is sometimes used interchangeably.However, some authors make the distinction that the bond-dissociation energy (D 0) refers to the enthalpy change at 0 K, while the term bond-dissociation enthalpy is used for the enthalpy change at 298 K (unambiguously denoted DH° 298).

  5. Bond energy - Wikipedia

    en.wikipedia.org/wiki/Bond_energy

    The strength of a bond can be estimated by comparing the atomic radii of the atoms that form the bond to the length of bond itself. For example, the atomic radius of boron is estimated at 85 pm, [10] while the length of the B–B bond in B 2 Cl 4 is 175 pm. [11] Dividing the length of this bond by the sum of each boron atom's radius gives a ratio of

  6. Force field (chemistry) - Wikipedia

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

    Part of force field of ethane for the C-C stretching bond. In the context of chemistry, molecular physics, physical chemistry, and molecular modelling, a force field is a computational model that is used to describe the forces between atoms (or collections of atoms) within molecules or between molecules as well as in crystals.

  7. Transition state theory - Wikipedia

    en.wikipedia.org/wiki/Transition_state_theory

    In chemistry, transition state theory (TST) explains the reaction rates of elementary chemical reactions. The theory assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated transition state complexes. [1] TST is used primarily to understand qualitatively how chemical reactions take place.

  8. Ethane - Wikipedia

    en.wikipedia.org/wiki/Ethane

    Ethane (US: / ˈ ɛ θ eɪ n / ETH-ayn, UK: / ˈ iː θ eɪ n / EE-thayn) is a naturally occurring organic chemical compound with chemical formula C 2 H 6. At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petrochemical by ...

  9. Henry's law - Wikipedia

    en.wikipedia.org/wiki/Henry's_law

    In his 1803 publication about the quantity of gases absorbed by water, [1] William Henry described the results of his experiments: … water takes up, of gas condensed by one, two, or more additional atmospheres, a quantity which, ordinarily compressed, would be equal to twice, thrice, &c. the volume absorbed under the common pressure of the atmosphere.