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In chemistry, the molar mass (M) (sometimes called molecular weight or formula weight, but see related quantities for usage) of a chemical compound is defined as the ratio between the mass and the amount of substance (measured in moles) of any sample of the compound. [1] The molar mass is a bulk, not molecular, property of a substance.
An example batch calculation may be demonstrated here. The desired glass composition in wt% is: 67 SiO 2, 12 Na 2 O, 10 CaO, 5 Al 2 O 3, 1 K 2 O, 2 MgO, 3 B 2 O 3, and as raw materials are used sand, trona, lime, albite, orthoclase, dolomite, and borax. The formulas and molar masses of the glass and batch components are listed in the following ...
Thomas Graham. Graham's law of effusion (also called Graham's law of diffusion) was formulated by Scottish physical chemist Thomas Graham in 1848. [1] Graham found experimentally that the rate of effusion of a gas is inversely proportional to the square root of the molar mass of its particles. [1]
M is the molar mass of the solvent. T b is boiling point of the pure solvent in kelvin. ΔH vap is the molar enthalpy of vaporization of the solvent. Through the procedure called ebullioscopy, a known constant can be used to calculate an unknown molar mass. The term ebullioscopy means "boiling measurement" in Latin.
The values are organized in a format that makes them readable by a thermodynamic calculation program or for use in a spreadsheet. For example, the Excel-based thermodynamic database FREED creates the following type of datafile, here for a standard pressure of 1 atm. Thermodynamic datafile for MgCl 2 (c,l,g) from FREED. Some values have ...
Each element has an atomic mass, and considering molecules as collections of atoms, compounds have a definite molecular mass, which when expressed in daltons is numerically equal to the molar mass in g/mol. By definition, the atomic mass of carbon-12 is 12 Da, giving a molar mass of 12 g/mol.
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.
By utilizing MALS in conjunction with a concentration detector as described above, one create a log-log plot of the root-mean-square radius vs molar mass. The slope of this plot yields the branching ratio, g. [28] In addition to branching, the log-log plot of size vs. molar mass indicates the shape or conformation of a macromolecule.