Weight, atomic molecular

This reaction has often reached explosive proportions in the laboratory. Several methods were devised for controlling it between 1940 and 1965. For fluorination of hydrocarbons of low (1—6 carbon atoms) molecular weight at room temperature or below by these methods, yields as high as 80% of perfluorinated products were reported together with partially fluorinated species (9—11). However, fluorination reactions in that eta involving elemental fluorine with complex hydrocarbons at elevated temperatures led to appreciable cleavage of the carbon—carbon bonds and the yields invariably were only a few percent. 

Hydrocarbon Carbon atoms Molecular weight Boiling pc °C... 

This is either an (M + 1)+ or an (M - -18)+ ion, depending upon the relative proton affinities of the analyte and ammonia. The molecular weight is therefore either 221 or 204 Da. Since the molecule contains an even number of nitrogen atoms, it must have an even molecular weight. The molecular species must therefore be (M - -18)+ and so the molecular weight is 204 Da. 

Ans. The atomic weight of fluorine is 19.0 amu, as seen in the periodic table or a table of atomic weights. The molecular weight of fluorine, corresponding to F2, is twice that value, 38.0amu. 

The reactive nature of compound 22 is illustrated by the series of transformations shown in Scheme 7.12, in which its Zr—C bond reacts selectively with electrophilic reagents to produce a-haloboronates 36—38. Compound 22 also catalyzes the polymerization of styrene. The polymers thus obtained had weight-average molecular masses in the range 75000—100000 with polydispersities of 1.8—2.1. An X-ray analysis of 22 confirmed it to be a four-coordinate Zr complex with two cyclopentadienyl rings, chlorine, and the aliphatic C-l carbon atom as the ligands (Fig. 7.4). 

Approximate amount, quantity, or figure amu = atomic mass units, or for heavy elements average mass units, aw = atomic weight mw = molecular weight... 

MOLECULAR WEIGHT, (atomic weight.) The weight in grams of an element, which equals one mole of atoms. 

The moleoular weight of a compoimd is, with very few exceptions, identical with its atomic weight. The molecular volume or the space occupied by the combining proportion of a compound is, with very exceptions, equal to that occupied by two combining proportions, or one molecule, of hydrogen. Hence the law—equal volumes qfM gases and mysours contain, at the same temperature and pressure, an equal number of mole-eules. 

Atomic weigH =>85 B. Molecular weight tall. Molecular volume Cn, lliire weighs critht, Mas not bem solidified. Ligvgfies at 16 6 C., under a pressure of 4 atmo heres. Atomicity. Svidenee fatomieity, HCl. 

Anions are bulkier than cations and have larger ionic radii than cations of the same atomic (molecular) weight and number of charges. This is why they are also more polarizable. 

An unknown substance, X, was isolated from rabbit muscle. Its structure was determined from the following observations and experiments. Qualitative analysis showed that X was composed entirely of C, H, and 0. A weighed sample of X was completely oxidized, and the H20 and C02 produced were measured this quantitative analysis revealed that X contained 40.00% C, 6.71% H, and 53.29% O by weight. The molecular mass of X, determined by mass spectrometry, was 90.00 u (atomic mass units see Box 1-1). Infrared spectroscopy showed that X contained one double bond. X dissolved readily in water to give an acidic solution the solution demonstrated optical activity when tested in a polarimeter. 

Indices Based on Atom-Pair Weighting Atom pairs (ij) in a molecular graph can be assigned a weight wy. The topological distance is a possible weighting... 

Older books and chemical journals used the terms atomic weight and molecular weight rather than atomic mass and molar mass. Because "weight" is a force rather than a mass, such usage is potentially confusing and is now discouraged, but many chemists trained in an earlier time still use the old terms, so you may encounter them. 

The average mass of all molecules of a compound is its molecular mass (formerly called molecular weight). The molecular mass of a compound is calculated by multiplying the atomic mass of each element by the relative number of atoms of the element, then adding all the values obtained for each element in the compound. For example, the molecular mass of NH3 is 14.0 + 3 x 1.0 = 17.0. For another example, consider the following calculation of the molecular mass of ethylene, C2H4 ... 

Approximation to the sum of VDW surface areas of pure hydrogen bond donors Approximation to the sum of VDW surface areas of hydrophobic atoms Molecular weight... 

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