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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.
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.
b is the molality of the solution. Through cryoscopy, a known constant can be used to calculate an unknown molar mass. The term "cryoscopy" means "freezing measurement" in Greek. Freezing point depression is a colligative property, so ΔT depends only on the number of solute particles dissolved, not the nature of those particles.
The mass average molar mass (often loosely termed weight average molar mass) is another way of describing the molar mass of a polymer. Some properties are dependent on molecular size, so a larger molecule will have a larger contribution than a smaller molecule.
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.
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.
The molar mass of a substance depends not only on its molecular formula, but also on the distribution of isotopes of each chemical element present in it. For example, the molar mass of calcium-40 is 39.962 590 98 (22) g/mol, whereas the molar mass of calcium-42 is 41.958 618 01 (27) g/mol, and of calcium with the normal isotopic mix is 40.078(4 ...
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 ...