Specific Heat of Gases at High Temperatures

Abstract

EVIDENCE has been accumulating in my laboratory that combustion is in general far from being complete at the moment of maximum pressure in closed vessel gaseous explosions even under the best experimental conditions, and that consequently specific heat values for gases at high temperatures determined by the explosion method are much larger than the true values. Much of this evidence has rested upon certain assumptions, such, for example, as that the specific heats of various diatomic gases constituting the diluents in explosive mixtures are practically the same over any given temperature range.¹ But recently Messrs. J. R. Brown and A. H. El Din have completed a carefully conducted and extended series of experiments which seem to offer conclusive proof that incomplete combustion at the moment of attainment of maximum pressure in closed vessel explosions is generally so large as to make the explosion method as usually employed unreliable for specific heat determinations.