molecular weight

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weight

 [wāt]
1. heaviness; the degree to which a body is drawn toward the earth by gravity. (See also Tables of Weights and Measures in the Appendix.) Abbreviated wt.
2. in statistics, the process of assigning greater importance to some observations than to others, or a mathematical factor used to apply such a process.
apothecaries' weight see apothecaries' system.
atomic weight the sum of the masses of the constituents of an atom, expressed in atomic mass units (or daltons), in SI units (i.e., kilograms), or as a dimensionless ratio derived by comparing the mass to the mass of an atom of carbon-12, which is taken as 12.000. Abbreviated At wt.
avoirdupois weight see avoirdupois system.
equivalent weight the amount of substance that combines with or displaces 8.0 g of oxygen (or 1.008 g of hydrogen), usually expressed in grams; for acid/base reactions, one equivalent donates or receives a mole of protons and the equivalent weight is the ratio of the molecular weight to the number of protons involved in the reaction. For oxidation-reduction reactions, one equivalent donates or receives a mole of electrons and the equivalent weight is the ratio of the molecular weight to the number of electrons involved in the reaction.
gram molecular weight the molecular weight of a substance expressed in grams; one gram molecular weight of a molecular substance contains one mole of molecules. See also mole1.
low birth weight (LBW) see under infant.
molecular weight the weight of a molecule of a chemical compound as compared with the weight of an atom of carbon-12; it is equal to the sum of the weights of its constituent atoms and is dimensionless. Abbreviated Mol wt or MW. Although widely used, the term is not technically correct; relative molecular mass is preferable.
very low birth weight (VLBW) see under infant.

mo·lec·u·lar weight (mol wt, MW),

the sum of the atomic weights of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units.
See also: atomic weight.

mo·lec·u·lar weight

(mŏ-lekyū-lăr wāt)
The sum of the atomic weights of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units.
See also: atomic weight
Synonym(s): molecular weight ratio, relative molecular mass.

molecular weight

The sum of the weights of all the atoms in the molecule.

mo·lec·u·lar weight

(mol wt, MW) (mŏ-lekyū-lăr wāt)
The sum of the atomic weights of all the atoms constituting a molecule.
Synonym(s): molecular weight ratio, relative molecular mass.
References in periodicals archive ?
Caption: Figure 5: Molar mass (mean [+ or -] deviation) of the PLGA plates in the 0,15,30, 60, and 120 days of degradation in PBS solution for PLGA_lowT (a) and PLGA_highT (b).
[M.sub.AAC] is the molar mass of acryl acid chloride (g/Mol), [n.sub.AAC] is the molar amount of acryl acid chloride, [M.sub.HCl] is the molar mass hydrogen chloride (g/Mol), [M.sub.G] is the molar mass of glycerol (g/Mol), [n.sub.G] is the molar amount of substance of glycerol, [M.sub.R] is the molar mass of castor oil (g/Mol), and [n.sub.R] is the molar amount of substance of castor oil.
Molar mass distribution was determined at the end of the fermentation with a weight average molecular weight [M.sub.w] = 150 kD and a polydispersity index of [P.sub.i] of 2.1.
Step 4: Relationship between molar mass and relative atomic mass was [sup.12]C Why is the number standing for molar mass in grams for any atom the same with the number standing for the relative mass in atomic mass units for a single atom?
Substituting Equation 3 into Equations 1 and 2 and dividing the R value by the molar mass of humid air (Equation 4), the exergy value of humid air in buildings (per kilogram of humid air) can be calculated as functions of air temperature T and humidity ratio W by using Equations 5 and 6.
Constants associated with the density equation for normal hydrogen i [a.sub.i] [b.sub.i] [c.sub.i] 1 0.058 884 60 1.325 1.0 2 -0.061 361 11 1.87 1.0 3 -0.002 650 473 2.5 2.0 4 0.002 731 125 2.8 2.0 5 0.001 802 374 2.938 2.42 6 -0.001 150 707 3.14 2.63 7 0.958 852 8 x [10.sup.-4] 3.37 3.0 8 -0.1109040 0 x [10.sup.-6] 3.75 4.0 9 0.126 440 3 x [10.sup.-9] 4.0 5.0 Molar Mass: M = 2.015 88 g/mol Universal Gas Constant: R = 8.314 472 J/(mol.
Each presents a discussion of the state of research of a different aspect of the composition, molar mass, molar mass distribution, structure, morphology, molecular organization, and dynamics that characterize polymers.
(1991) was the first to use a molar mass distribution for the asphaltenes.
The Keynote Address, entitled "Ultrafast Synthesis of Ultrahigh Molar Mass Polymers by SET-LRP of Acrylates, Methacrylates and Vinyl Halides at Room Temperature," will be delivered by Dr.