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  2. Standard enthalpy of formation - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_formation

    All elements in their reference states (oxygen gas, solid carbon in the form of graphite, etc.) have a standard enthalpy of formation of zero, as there is no change involved in their formation. The formation reaction is a constant pressure and constant temperature process. Since the pressure of the standard formation reaction is fixed at 1 bar ...

  3. Standard enthalpy of reaction - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_reaction

    Standard enthalpy of formation is the enthalpy change when one mole of any compound is formed from its constituent elements in their standard states. The enthalpy of formation of one mole of ethane gas refers to the reaction 2 C (graphite) + 3 H 2 (g) → C 2 H 6 (g).

  4. Heat of formation group additivity - Wikipedia

    en.wikipedia.org/wiki/Heat_of_formation_group...

    1,5 pentane interference correction +1.60 ; in kcal/mol and 298 K. The following example illustrates how these values can be derived. The experimental heat of formation of ethane is -20.03 kcal/mol and ethane consists of 2 P groups.

  5. Thermodynamic databases for pure substances - Wikipedia

    en.wikipedia.org/wiki/Thermodynamic_databases...

    Regardless of the equation format, the heat of formation of a compound at any temperature is ΔH° form at 298.15 K, plus the sum of the heat content parameters of the products minus the sum of the heat content parameters of the reactants. The C p equation is obtained by taking the derivative of the heat content equation.

  6. Ethane (data page) - Wikipedia

    en.wikipedia.org/wiki/Ethane_(data_page)

    Std enthalpy change of formation, Δ f H o liquid? kJ/mol Standard molar entropy, S o liquid: 126.7 J/(mol K) Heat capacity, c p: 68.5 J/(mol K) at −179 °C Gas properties Std enthalpy change of formation, Δ f H o gas: −83.8 kJ/mol Standard molar entropy, S o gas: 229.6 J/(mol K) Enthalpy of combustion, Δ c H o: −1560.7 kJ/mol Heat ...

  7. Van 't Hoff equation - Wikipedia

    en.wikipedia.org/wiki/Van_'t_Hoff_equation

    The Van 't Hoff equation relates the change in the equilibrium constant, K eq, of a chemical reaction to the change in temperature, T, given the standard enthalpy change, Δ r H ⊖, for the process. The subscript r {\displaystyle r} means "reaction" and the superscript ⊖ {\displaystyle \ominus } means "standard".

  8. Ethane - Wikipedia

    en.wikipedia.org/wiki/Ethane

    Ethane (US: / ˈ ɛ θ eɪ n / ETH-ayn, UK: / ˈ iː-/ EE-) 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-product of petroleum ...

  9. Miedema's model - Wikipedia

    en.wikipedia.org/wiki/Miedema's_model

    Miedema's model is a semi-empirical approach for estimating the heat of formation of solid or liquid metal alloys and compounds in the framework of thermodynamic calculations for metals and minerals. [1]