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  2. Group-contribution method - Wikipedia

    en.wikipedia.org/wiki/Group-contribution_method

    The simplest form of a group-contribution method is the determination of a component property by summing up the group contributions : [] = +.This simple form assumes that the property (normal boiling point in the example) is strictly linearly dependent on the number of groups, and additionally no interaction between groups and molecules are assumed.

  3. UNIFAC - Wikipedia

    en.wikipedia.org/wiki/UNIFAC

    The activity of a real chemical is a function of the thermodynamic state of the system, i.e. temperature and pressure. Equipped with the activity coefficients and a knowledge of the constituents and their relative amounts, phenomena such as phase separation and vapour-liquid equilibria can be calculated. UNIFAC attempts to be a general model ...

  4. UNIQUAC - Wikipedia

    en.wikipedia.org/wiki/UNIQUAC

    In a quaternary mixture there are six such parameters (1–2,1–3,1–4,2–3,2–4,3–4) and the number rapidly increases with additional chemical components. The empirical parameters are obtained by a correlation process from experimental equilibrium compositions or activity coefficients, or from phase diagrams, from which the activity ...

  5. Reaction rate constant - Wikipedia

    en.wikipedia.org/wiki/Reaction_rate_constant

    where A and B are reactants C is a product a, b, and c are stoichiometric coefficients,. the reaction rate is often found to have the form: = [] [] Here ⁠ ⁠ is the reaction rate constant that depends on temperature, and [A] and [B] are the molar concentrations of substances A and B in moles per unit volume of solution, assuming the reaction is taking place throughout the volume of the ...

  6. Equating coefficients - Wikipedia

    en.wikipedia.org/wiki/Equating_coefficients

    In mathematics, the method of equating the coefficients is a way of solving a functional equation of two expressions such as polynomials for a number of unknown parameters. It relies on the fact that two expressions are identical precisely when corresponding coefficients are equal for each different type of term.

  7. Stoichiometry - Wikipedia

    en.wikipedia.org/wiki/Stoichiometry

    CH 4 + 2 O 2 → CO 2 + 2 H 2 O. Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. This particular chemical equation is an example of complete combustion. Stoichiometry measures these quantitative relationships, and is used to determine the amount of ...

  8. Amagat's law - Wikipedia

    en.wikipedia.org/wiki/Amagat's_law

    Amagat's law states that the extensive volume V = Nv of a gas mixture is equal to the sum of volumes V i of the K component gases, if the temperature T and the pressure p remain the same: [1] [2] (,) = = (,). This is the experimental expression of volume as an extensive quantity.

  9. Trinomial expansion - Wikipedia

    en.wikipedia.org/wiki/Trinomial_expansion

    Layers of Pascal's pyramid derived from coefficients in an upside-down ternary plot of the terms in the expansions of the powers of a trinomial – the number of terms is clearly a triangular number. In mathematics, a trinomial expansion is the expansion of a power of a sum of three terms into monomials. The expansion is given by