Heat of combustion of Teflon in fluorine. A check on the heat of formation of carbon tetrafluoride

Abstract

The heat of combustion in fluorine of a Teflon sample whose heat of formation was previously known has been determined as -246.84 ± 0.07 kcal. mole-1. This information combined with other available thermodynamic data gives °[CF4( g) ] = -223 ± 1 kcal. mole -1.In RECENT years numerous workers have determined the heat of formation of CF4(g) both by direct and indirect methods. The early value of zlfí/'[CF4(g) ] reported by von Wartenberg (19) of -162 ± 2 kcal. mole-1 by the direct combination of the elements was in error owing to the formation of higher fluorides. During the period of 1954-65, the reported values for Ai/f[CF4(g)] approached -219.0

Ideal Gas Thermodynamic Properties of Eight Chloro- and Fluoromethanes

“…for reaction 9-1 determined by Scott, Good, and Waddington (1955), one can calculate 6.Hr(C 2F-4, poly, 298)=-199.0± 0.9 kcal mol-to Incorporating this value with 6.HrO(298) for reaction 9-6 yields 6.HF(CF .. , g, 298)=-222.9± 0.9 kcal mol-t. Domalski and Armstrong (1967) studied the same reaction (9-6) but with 15 atm fluorine which, they report; suqJn:~88ed Lhe fUrIllaLiull uf higher pedluolOalkanes. They obtained 6.HrO(298)=-247.92±0.07 kcal mol-I [compare to 6.HrO(298)=-246.84 kcal mol-1 of Wood, Lagow, and Margrave (1967)]. As above, this yields 6.HF(CF .. , g, 298)=-223.5±0.9 kcal mol-to These workers have also studied the enthalpy of formation of CF .. (reaction 9-7) with 15--: 20 atm fluorine.…”

High Accuracy Quantum Chemical and Thermochemical Network Data for the Heats of Formation of Fluorinated and Chlorinated Methanes and Ethanes

“…[C 2 F 4 ] n was used to determine the heat of formation of CF 4 by Waddington and associates, , Cox and co-workers, Wood et al, and Domalski . Because these reactions were part of our network, it was inevitable to also fit the heat of formation of [C 2 F 4 ] n .…”

“…b During the initial solution of the TN, these reactions were considered by the iterative process; however, they were excluded from the final TN because they were both influential, according to the calculated DFBETAs, and challenged by other studies in the field (see text). [C 2 F 4 ] n was used to determine the heat of formation of CF 4 by Waddington and associates, 78,81 Cox and co-workers, 82 Wood et al, 83 and Domalski. 79 Because these reactions were part of our network, it was inevitable to also fit the heat of formation of [C 2 F 4 ] n .…”