|
( Molar mass)
Molar mass, symbol M,[1] is the mass of one mole of a substance (chemical element or chemical compound).[2] It is a physical property which is characteristic of each pure substance. The base SI unit for mass is the kilogram[1] but, for both practical and historical reasons, molar masses are almost always quoted in grams per mole (g/mol or g&_160;mol–1), especially in chemistry. Molar mass is closely related to the molecular weight or relative molar mass (Mr) of a compound, and to the relative atomic masses or the standard atomic weights of its constituent elements. However, it should be distinguished from the molecular mass , which is the mass of one molecule (of any single isotopic composition) and is not directly related to the atomic mass, the mass of one atom (of any single isotope). The dalton, symbol Da, is also sometimes used as a unit of molar mass, especially in biochemistry, with the definition 1&_160;Da&_160;= 1&_160;g/mol, despite the fact that it is strictly a unit of molecular mass (1&_160;Da&_160;= 1.660&_160;538&_160;782(83)×10–27&_160;kg).[3][4] Molar masses are almost never measured directly. They may be calculated from standard atomic weights, and are often listed in chemical catalogues and on material safety data sheets (MSDS). Molar masses typically vary between The molar mass of atoms of an element is given by the standard atomic weight of the element[5] multiplied by the molar mass constant, Mu&_160;= 1×10–3&_160;kg/mol&_160;= 1&_160;g/mol[6]
|
Molar mass Subcategories
Molar mass Articles
|
|
