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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. Atomic ratio - Wikipedia

    en.wikipedia.org/wiki/Atomic_ratio

    The atomic ratio is a measure of the ratio of atoms of one kind (i) to another kind (j). A closely related concept is the atomic percent (or at.%), which gives the percentage of one kind of atom relative to the total number of atoms. [1]

  6. 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 ...

  7. Standard temperature and pressure - Wikipedia

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

    V m = 10.7316 × 519.67 / 14.696 = 379.48 ft 3 /lbmol at 60 °F and 14.696 psi (or about 0.8366 ft 3 /gram mole) V m = 10.7316 × 519.67 / 14.730 = 378.61 ft 3 /lbmol at 60 °F and 14.73 psi Technical literature can be confusing because many authors fail to explain whether they are using the ideal gas constant R , or the specific gas constant R s .

  8. Van der Waals equation - Wikipedia

    en.wikipedia.org/wiki/Van_der_Waals_equation

    One way to write the van der Waals equation is: [8] [9] [10] = where is pressure, is temperature, and = / is molar volume. In addition is the Avogadro constant, is the volume, and is the number of molecules (the ratio / is a physical quantity with base unit mole (symbol mol) in the SI).

  9. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    As an example, a measured NO x concentration of 45 ppmv in a dry gas having 5 volume % O 2 is: 45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv of NO x. when corrected to a dry gas having a specified reference O 2 content of 3 volume %. Note: The measured gas concentration C m must first be corrected to a dry basis before using the above equation.