Chemical formulas history

When Williamson and his contemporaries thought about the symbols that appeared in the chemical formulas they bandied about, just what did they have "in mind" To provide even a provisional answer to this question, we need briefly to review the early history of the atomic theory in chemistry. ... 

In 1890 Walfr. Petersson published a complete history of gadolinite and a thorough investigation of its chemical and mineralogical properties. His analyses, like those of F. A. Genth and C. W. Blomstrand, led to the formula ... 

A highly focused account is found in O, Theodor Benfey, From Vital Force to Structural Formulas (Philadelphia American Chemical Society 1964). A broader account is found in chapter 7 of Brock, Norton History of Chemistry. 

These have only one true stationary-state solution, ass = pss = 0 (as t - go), corresponding to complete conversion of the initial reactant to the final product C. This stationary or chemical equilibrium state is a stable node as required by thermodynamics, but of course that tells us nothing about how the system evolves in time. If e is sufficiently small, we may hope that the concentrations of the intermediates will follow pseudo-stationary-state histories which we can identify with the results of the previous sections. In particular we may obtain a guide to the kinetics simply by replacing p by p0e et wherever it occurs in the stationary-state and Hopf formulae. Thus at any time t the dimensionless concentrations a and p would be related to the initial precursor concentration by... 

For accounts of the history of the development of structural formulas see Nye MJ (1993) From chemical philosophy to theoretical chemistry. University of California Press, Berkeley, CA Russell CA (1996) Edward Frankland chemistry, controversy and conspiracy in Victorian England. Cambridge University Press, Cambridge... 

Near rich limits of hydrocarbon flames, soot is sometimes produced in the flame. The carbonaceous particles—or any other solid particles— easily can be the most powerful radiators of energy from the flame. The function k(t) is difficult to compute for soot radiation for use in equation (21) because it depends on the histories of number densities and of size distributions of the particles produced for example, an approximate formula for Ip for spherical particles of radius with number density surface emissivity 6, and surface temperature is Ip = Tl nrle ns) [50]. These parameters depend on the chemical kinetics of soot production—a complicated subject. Currently it is uncertain whether any of the tabulated flammability limits are due mainly to radiant loss (since convective and diffusive phenomena will be seen below to represent more attractive alternatives), but if any of them are, then the rich limits of sooting hydrocarbon flames almost certainly can be attributed to radiant loss from soot. 

Sample a chemical description of the sample, plus its source and any pre-treatment. Also, the purity, chemical composition and formula, if known. Other important items to note are the particle size, whether the sample has been mixed with a binder (and, if so, what it has been mixed with and in what ratio) and the history of the sample. 

Today s chemist, if he wishes to gain an over-all and general view of the literature of chemistry, to learn about a specific class of chemical literature, such as abstract journals, monograph series, formula lexicons, or compilations, or to inquire into the history, scope, or quality of a specific source of chemical information, is fortunate in having at his call a number of basic books in this special field (5, 19,21 2Ji),... 

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