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  2. Standard molar entropy - Wikipedia

    en.wikipedia.org/wiki/Standard_molar_entropy

    The standard molar entropy of a gas at STP includes contributions from: [2] The heat capacity of one mole of the solid from 0 K to the melting point (including heat absorbed in any changes between different crystal structures). The latent heat of fusion of the solid. The heat capacity of the liquid from the melting point to the boiling point.

  3. Mole fraction - Wikipedia

    en.wikipedia.org/wiki/Mole_fraction

    When expressed in percent, it is known as the mole percent or molar percentage (unit symbol %, sometimes "mol%", equivalent to cmol/mol for 10 −2). The mole fraction is called amount fraction by the International Union of Pure and Applied Chemistry (IUPAC) [1] and amount-of-substance fraction by the U.S. National Institute of Standards and ...

  4. Molar volume - Wikipedia

    en.wikipedia.org/wiki/Molar_volume

    The ideal gas equation can be rearranged to give an expression for the molar volume of an ideal gas: = = Hence, for a given temperature and pressure, the molar volume is the same for all ideal gases and is based on the gas constant: R = 8.314 462 618 153 24 m 3 ⋅Pa⋅K −1 ⋅mol −1, or about 8.205 736 608 095 96 × 10 −5 m 3 ⋅atm⋅K ...

  5. Standard state - Wikipedia

    en.wikipedia.org/wiki/Standard_state

    The standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions.A degree sign (°) or a superscript Plimsoll symbol (⦵) is used to designate a thermodynamic quantity in the standard state, such as change in enthalpy (ΔH°), change in entropy (ΔS°), or change in Gibbs free energy (ΔG°).

  6. Atomic ratio - Wikipedia

    en.wikipedia.org/wiki/Atomic_ratio

    A closely related concept is the atomic percent ... For example, theoretically, a 100% doping ratio of Yb: Y 3 Al 5 O 12 is pure Yb 3 Al 5 O 12. The doping fraction ...

  7. Amount of substance - Wikipedia

    en.wikipedia.org/wiki/Amount_of_substance

    Historically, the mole was defined as the amount of substance in 12 grams of the carbon-12 isotope.As a consequence, the mass of one mole of a chemical compound, in grams, is numerically equal (for all practical purposes) to the mass of one molecule or formula unit of the compound, in daltons, and the molar mass of an isotope in grams per mole is approximately equal to the mass number ...

  8. Stoichiometry - Wikipedia

    en.wikipedia.org/wiki/Stoichiometry

    Reaction stoichiometry describes the 2:1:2 ratio of hydrogen, oxygen, and water molecules in the above equation. The molar ratio allows for conversion between moles of one substance and moles of another. For example, in the reaction 2 CH 3 OH + 3 O 22 CO 2 + 4 H 2 O. the amount of water that will be produced by the combustion of 0.27 moles ...

  9. Standard temperature and pressure - Wikipedia

    en.wikipedia.org/wiki/Standard_temperature_and...

    In chemistry, IUPAC changed its definition of standard temperature and pressure in 1982: [1] [2] Until 1982, STP was defined as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 1 atm (101.325 kPa).