Molecular formula weight

It is often difficult to know the structures of all the by-products therefore, the percentage atom economy may be determined by dividing the molecular formula weight (MFW) of the desired product by the sum of the MFWs of all the reactants and multiplying by 100. 

Compound Empirical Molecular formula weight From mp °C) bp (°C) Solubility in water... 

For modeling surface adsorption using the surface complexation theory, we need properties of the surfaces as well as complexation constants for the sorbant. Surface properties include site density, surface areas, and molecular formula weight. If we use the triple layer model, capacitance data are also needed see Chapter 7 for more details. 

Yellow needles, yielding a violet solution in water. Mono-molecular (formula weight 268.24) in solution, dimerized (formula weight 536.68) as a solid. Recrystalllzable from IN KOH. Dry, pure preparations that have been washed with pure methanol and ether are stable practically idefinitely if kept in a clean glass container under vacuum. The containers described in Part I, p. 75, are recommended (G. Brauer, private commimication). 

Mole—the molecular formula weight of any substance expressed in grams. 

The mole is often referred to as a chemist s unit of quantity. Counting atoms is a difficult process and beyond the scope of most calculators, but measuring the mass of a sample is easy when we can relate the number of atoms in a sample to its mass. This is the unique purpose of the mole. A mole of any substance is its molecular formula weight expressed in grams. Avogadro s number s a universal constant that states the number of molecules in a mole Nq = 6.023 x 10 molecules/mole. One mole (abbreviated mol) of any element (chemical compound) has the same number of chemical particles as one mole of another element (chemical compound). In other words, 1 mole of any compound contains 6.02 x 10 molecules. Review the following problem using the mole concept. 

A mole is used to measure the mass of a sample by relating the number of atoms in a sample to its mass. A mole of any substance is its molecular formula weight expressed in grams. Avogadro s number is a universal constant that states the number of molecules in a mole Nq = 6.023 x 10 molecules/mole. 

Factual databases may provide the electronic version of printed catalogs on chemical compoimds. The catalogs of different suppliers of chemicals serve to identify chemical compounds with their appropriate synonyms, molecular formulas, molecular weight, structure diagrams, and - of course - the price. Sometimes the data are linked to other databases that contain additional information. Structure and substructure search possibihties have now been included in most of the databases of chemical suppliers. 

The problem of perception complete structures is related to the problem of their representation, for which the basic requirements are to represent as much as possible the functionality of the structure, to be unique, and to allow the restoration of the structure. Various approaches have been devised to this end. They comprise the use of molecular formulas, molecular weights, trade and/or trivial names, various line notations, registry numbers, constitutional diagrams 2D representations), atom coordinates (2D or 3D representations), topological indices, hash codes, and others (see Chapter 2). 

Empirical molecular formulas and molecular weights usual identify a whole class of compounds (chemical isomers) rather than a single structure. Further-... 

The analyses which follow are arranged in the order in which they would be applied to a newly discovered substance, the estimation of the elements present and molecular weight deter-minations(f.e., determination of empirical and molecular formulae respectively) coming first, then the estimation of particular groups in the molecule, and finally the estimation of special classes of organic compounds. It should be noted, however, that this systematic order differs considerably from the order of experimental difficulty of the individual analyses. Consequently many of the later macro-analyses, such as the estimation of hydroxyl groups, acetyl groups, urea, etc. may well be undertaken by elementary students, while the earlier analyses, such as estimation of elements present in the molecule, should be reserved for more senior students. 

A second example concerns different compounds that have the same molecular weight but different molecular formulas such as heptane and cyclopropyl acetate... 

Molecular Formula. For compounds consisting of discrete molecules, a formula in accordance with the correct molecular weight of the compound should be used. 

Fragment ion. An electrically charged dissociation product of an ionic fragmentation. Such an ion may dissociate further to form other electrically charged molecular or atomic moieties of successively lower formula weight. 

The vapor density of acetic acid suggests a molecular weight much higher than the formula weight, 60.06. Indeed, the acid normally exists as a dimer (4), both in the vapor phase (5) and in solution (6). This vapor density anomaly has important consequences in engineering computations, particularly in distillations. 

Aldehyde CAS Registry Number Molecular formula Molecular weight Melting point, °C Boiling point, °C Solubiity, g/lOOg water... 

The Merck Index Online Merck Co., Inc. Dialog, CIS, BRS, the online counterpart to the printed 11th ed. of The Merck Index, records contain molecular formulas and weights, systematic... 

Name Common designation Molecular formula CAS Registry Number Molecular weight... 

Name CAS Registry Number Molecular formula Molecular weight Physical form at 25°C Boiling point, Freezing point, °C Density, g/mL Typical Assay Flash point, °C Molten color APHA... 

Compound CAS Registry Number 9D bp/mp, °C Molecular formula Molecular weight... 

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