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Molar mass: 121.9529 g/mol ... White, crystalline powder Density: 2.566 g/cm 3, solid Melting point: 1,800 °C (3,270 °F; 2,070 K) ... These organic molecules act as ...
The interest stems from that accurate measurements of the unit cell volume, atomic weight and mass density of a pure crystalline solid provide a direct determination of the Avogadro constant. [3] The CODATA recommended value for the molar volume of silicon is 1.205 883 199 (60) × 10 −5 m 3 ⋅mol −1, with a relative standard uncertainty of ...
For atoms or molecules of a well-defined molar mass M (in kg/mol), the number density can sometimes be expressed in terms of their mass density ρ m (in kg/m 3) as =. Note that the ratio M/N A is the mass of a single atom or molecule in kg.
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 number average molar mass is a way of determining the molecular mass of a polymer.Polymer molecules, even ones of the same type, come in different sizes (chain lengths, for linear polymers), so the average molecular mass will depend on the method of averaging.
Aluminium dihydrogenphosphate describes inorganic compounds with the formula Al(H 2 PO 4) 3. xH 2 O where x = 0 or 3. They are white solids. Upon heating these materials convert sequentially to a family of related polyphosphate salts including aluminium triphosphate (AlH 2 P 3 O 10. 2H 2 O), aluminium hexametaphosphate (Al 2 P 6 O 18), and aluminium tetrametaphosphate (Al 4 (P 4 O 12) 3).
Because a dalton, a unit commonly used to measure atomic mass, is exactly 1/12 of the mass of a carbon-12 atom, this definition of the mole entailed that the mass of one mole of a compound or element in grams was numerically equal to the average mass of one molecule or atom of the substance in daltons, and that the number of daltons in a gram ...
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 ...