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Standard molar entropy, S o liquid: 213.7J/(mol K) Heat capacity, [10] c p: 80—150 J/(mol·K) at 220—290 K Gas properties Std enthalpy change of formation, Δ f H o gas: −393.52 kJ/mol Standard molar entropy, S o gas: 213.79 J/(mol·K) Heat capacity, [11] [12] c p: 33.89 J/(mol K) at –75 °C 36.33 J/(mol K) at 0 °C 36.61 J/(mol K) at ...
Carbon dioxide was the first gas to be described as a discrete substance. In about 1640, [143] the Flemish chemist Jan Baptist van Helmont observed that when he burned charcoal in a closed vessel, the mass of the resulting ash was much less than that of the original charcoal.
ISO TR 29922-2017 provides a definition for standard dry air which specifies an air molar mass of 28,965 46 ± 0,000 17 kg·kmol-1. [2] GPA 2145:2009 is published by the Gas Processors Association. It provides a molar mass for air of 28.9625 g/mol, and provides a composition for standard dry air as a footnote. [3]
Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong–Petit limit of 25 J⋅mol ...
The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol ≈ 1 g/mol. For normal samples from Earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight [ 2 ] or the conventional atomic weight.
The molecular mass and relative molecular mass are distinct from but related to the molar mass. The molar mass is defined as the mass of a given substance divided by the amount of the substance, and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different ...
Ammonium carbamate is a chemical compound with the formula [NH 4][H 2 NCO 2] consisting of ammonium cation NH + 4 and carbamate anion NH 2 COO −.It is a white solid that is extremely soluble in water, less so in alcohol.
The concentrations of carbon dioxide in the atmosphere are expressed as parts per million by volume (abbreviated as ppmv, or ppm(v), or just ppm). To convert from the usual ppmv units to ppm mass (abbreviated as ppmm, or ppm(m)), multiply by the ratio of the molar mass of CO 2 to that of air, i.e. times 1.52 (44.01 divided by 28.96).