DETERMINATION OF THE C-O BOND ENERGY FROM THE HEATS OF COMBUSTION OF FOUR ALIPHATIC ETHERS

1965 ◽  
Author(s):  
J. W. Murrin ◽  
S. Goldhagen
1975 ◽  
Vol 30 (3) ◽  
pp. 347-355 ◽  
Author(s):  
P. Potzinger ◽  
A. Ritter ◽  
J. Krause

The appearance potentials for a large number of organosilicon ions have been measured. Combination of these values with thermochemical heats of combustion allow the determination of bond energy terms which may be used to calculate heats of formation for all silicon compounds containing hydrogen, alkyl and chlorine ligands. The bond dissoziation energies D(Si - H)= 89 ± 4, D(Si - C) = 85 ± 4 and D (Si - Si) =75 ± 8 kcal/Mol were found to be independent of the number of methylgroups attached to silicon. In addition the Si - Cl bond energy was found to be 116 and 104 kcal/Mol in (CH3)3SiCl and Cl3SiCl respectively.


1935 ◽  
Vol 8 (3) ◽  
pp. 456-469
Author(s):  
Archibald T. McPherson ◽  
Norman Bekkedahl

Abstract PREVIOUS investigators have employed two methods for determining the heat effects when rubber is vulcanized. In one method the heats of vulcanization are found by subtracting the heats of combustion of vulcanized rubber—sulfur compounds from the heats of combustion of the corresponding mixtures of rubber and sulfur before vulcanization (1, 10, 11). This method is limited in precision by reason of the fact that the differences thus obtained are at most only a few per cent of the measured heath of combustion. The other method, which has been used previously, involves the determination of the temperature rise which occurs when mixtures of rubber and sulfur are vulcanized. This method has, for the most part, been used for relative measurements, but Blake (2) has recently employed it for quantitative determinations of the heats of reaction of rubber with proportions of sulfur up to about 8 per cent by weight. Recently Daynes (7) has employed a similar method for measurements over a wider range of composition. This investigation was undertaken for the purpose of measuring the heath of reaction of rubber with different percentages of sulfur over the entire range of composition in which combination takes place. The study was exploratory in character, the aim being to make the measurements by direct means with emphasis on simplicity rather than refinement of calorimetric procedure.


1999 ◽  
Vol 121 (14) ◽  
pp. 3531-3532 ◽  
Author(s):  
Patrick Weis ◽  
Paul R. Kemper ◽  
Michael T. Bowers ◽  
Sotiris S. Xantheas
Keyword(s):  

Author(s):  
Vitaly V. Ovchinnikov ◽  
Alexey A. Kulakov ◽  
Irina G. Grigor′eva ◽  
Svetlana A. Maltseva

The heats of vaporization, combustion, formation, entropy and the heat capacities in different phases of different carbonic acids and their derivatives: acetates, esters with fatty radicals, two-, three- and four-basic acids (52 compounds) were analysed in the framework of one-parametric mathematic equations. The experimental data of all chosen one-, two-, three- and four-basic acids were analyzed. It was determined, that all thermodynamic functions of these types of compounds depend on the number of valence electrons N, from which the sum of lone electron pairs g as represented in the equations Δvap,c,fH° = i ±  f (N-g) and S°(Cp) = i ±  f (N-g) is excluded. The coefficients f in the first equations is in the range of 104-113 kJ mol-1 electron-1, that corresponds to the same values f in the equations, which are mentioned in our earlier papers on the determination of the heats of combustion of organic acids. As concerned of coefficient i in the received equations, necessary to note that situation is not synonymous as with the coefficient f. The magnitudes of this coefficient are different in the equations of vaporization, combustion, formation also as in the equations of entropy and the heat of capacity. On the base of literary experimental data we calculated the 29 new equations, which can be used for the calculation of the same thermodynamic functions for other new organic acids and especially bioorganic substances with the useful properties. Necessary to add, that the received equations can serve as additional material for the calculation of the bond energies of fatty acids and their derivatives in gas phase.


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