Thermal Data. IX. The Heats of Combustion of Hippuric and Succinic Acids and a Proposal for the Use of Hippuric Acid as a Secondary Standard in Combustion Calorimetry

1938 ◽  
Vol 60 (5) ◽  
pp. 1171-1177 ◽  
Author(s):  
Hugh M. Huffman
1937 ◽  
Vol 59 (11) ◽  
pp. 2144-2150 ◽  
Author(s):  
Hugh M. Huffman ◽  
Sidney W. Fox ◽  
Emory L. Ellis

1942 ◽  
Vol 15 (4) ◽  
pp. 874-878 ◽  
Author(s):  
W. A. Roth ◽  
Gerhilde Wirths ◽  
Hildegarde Berendt

Abstract Measurements of the heats of combustion and specific heats (between 20° and 50° C) of crude untreated Buna-S, highly degraded Buna-S, and cyclized Buna-S are reported. The heats of combustion are then discussed. A well defined relation exists between thermal data and changes which take place in Buna-S. In the case of specific heats, the values of which are less precise, the relation is not so clearly defined.


A method has been evolved for measuring the heats of combustion of spontaneously inflammable substances in the bomb calorimeter and applied to the following compounds: zinc dimethyl, zinc diethyl, zinc di- n -propyl, zinc di- n -butyl, cadmium dimethyl, boron trimethyl and aluminium trimethyl. The samples used were subjected to very thorough purification, revised melting points being given for cadmium dimethyl and aluminium trimethyl. The heats of formation, deduced by the application of additional thermal data, have been listed with all those so far determined for the metal alkyls, and the energies of dissociation and bond energies of the metal-carbon links estimated. This has entailed a recalculation of the heats of sublimation of aluminium and tin. From a comparison of the values obtained for the dissociation energies with evidence from spectroscopic and kinetic studies, a definite necessity for taking into account the energies required to promote the various elements to the states of maximum valency is apparent.


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