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  2. Thermodynamic activity - Wikipedia

    en.wikipedia.org/wiki/Thermodynamic_activity

    The relative activity of a species i, denoted a i, is defined [4] [5] as: = where μ i is the (molar) chemical potential of the species i under the conditions of interest, μ o i is the (molar) chemical potential of that species under some defined set of standard conditions, R is the gas constant, T is the thermodynamic temperature and e is the exponential constant.

  3. Activity coefficient - Wikipedia

    en.wikipedia.org/wiki/Activity_coefficient

    In thermodynamics, an activity coefficient is a factor used to account for deviation of a mixture of chemical substances from ideal behaviour. [1] In an ideal mixture, the microscopic interactions between each pair of chemical species are the same (or macroscopically equivalent, the enthalpy change of solution and volume variation in mixing is zero) and, as a result, properties of the mixtures ...

  4. Calconcarboxylic acid - Wikipedia

    en.wikipedia.org/wiki/Calconcarboxylic_acid

    Calconcarboxylic acid (IUPAC name 3-hydroxy-4-[(2-hydroxy-4-sulfonaphthalen-1-yl)diazenyl]naphthalene-2-carboxylic acid; commonly called Patton and Reeder's Indicator) is an azo dye that is used as an indicator for complexometric titrations of calcium with ethylenediaminetetraacetic acid (EDTA) in the presence of magnesium. [2]

  5. UNIFAC - Wikipedia

    en.wikipedia.org/wiki/UNIFAC

    By adding a correction factor, known as the activity (, the activity of the i th component) to the liquid phase fraction of a liquid mixture, some of the effects of the real solution can be accounted for. The activity of a real chemical is a function of the thermodynamic state of the system, i.e. temperature and pressure.

  6. Non-random two-liquid model - Wikipedia

    en.wikipedia.org/wiki/Non-random_two-liquid_model

    The non-random two-liquid model [1] (abbreviated NRTL model) is an activity coefficient model introduced by Renon and Prausnitz in 1968 that correlates the activity coefficients of a compound with its mole fractions in the liquid phase concerned. It is frequently applied in the field of chemical engineering to calculate phase equilibria.

  7. Calcium silicate - Wikipedia

    en.wikipedia.org/wiki/Calcium_silicate

    Unit cell of Ca 2 SiO 4. Color code: red (O), blue (Ca), gold (Si). As verified by X-ray crystallography, calcium silicate is a dense solid consisting of tetrahedral orthosilicate (SiO 4 4-) units linked to Ca 2+ via Si-O-Ca bridges. There are two calcium sites. One is seven coordinate and the other is eight coordinate. [11]

  8. Margules activity model - Wikipedia

    en.wikipedia.org/wiki/Margules_activity_model

    The Margules activity model is a simple thermodynamic model for the excess Gibbs free energy of a liquid mixture introduced in 1895 by Max Margules. [1] [2] After Lewis had introduced the concept of the activity coefficient, the model could be used to derive an expression for the activity coefficients of a compound i in a liquid, a measure for the deviation from ideal solubility, also known as ...

  9. Calcium carbonate - Wikipedia

    en.wikipedia.org/wiki/Calcium_carbonate

    where the initial state is the acid solution with no Ca 2+ (not taking into account possible CO 2 dissolution) and the final state is the solution with saturated Ca 2+. For strong acid concentrations, all species have a negligible concentration in the final state with respect to Ca 2+ and A − so that the neutrality equation reduces ...