THERMODYNAMIC PROPERTIES OF ROCKET COMBUSTION PRODUCTS

A review of previous studies of vapor species in the beryllium-oxygen-hydrogen system at high temperatures is presented. Mass spectrometric studies of the reaction of water vapor with beryllium oxide were carried out at temperatures up to 2600 K. A tentative lower limit of -181 kcal/mole for the heat of formation of Be(OH)2(g) at 298 K was derived from mass spectral data. A mixture of beryllium metal and beryllium oxide in a W eff sion cell in the mass spectrometer indicated Be(g) in the effusing vapor at temperatures up to 1800 K. No evidence for Be (g) and Be2O(g) was found in the same temperature range. Mass spectra for the Be-BeO mixture in the presence of water vapor contained no measurable intensities of BeOH(+) at 1800 K. A lower limit of -21 kcal/mole was tentatively derived for the heat of formation of BeOH(g) at 298 K. The vaporization of beryllium oxide and its reaction with W were studied from 2300-2600 K. The heats of s blimation of (BeO)3(g) and (BeO)4(g) at 2354 K determined by the second-law method are -180 and -198 kcal/mole, respectively. A new table of thermodynamic functions, based upon recently reported heat-content data, was compiled for condensed BeO. (Author)