DEPENDENCE OF THE HELMHOLZ ENERGY FROM THE TEMPERATURE OF FLASH N-ALKYL BENZENS

Abstract

The number of organic compounds has exceeded 40 million and further increases by 300 thousand each year. To ensure the fire safety and the accuracy of the production process design, as well as the safe storage and transportation of materials, it is necessary to determine the level of fire and explosion hazard of various substances. It is therefore extremely important to develop a method for determining the fire hazard indicators and thermodynamic properties of substances, based on the minimum amount of experimental data. To solve this problem we consider it necessary to determine the dependencies between the molecular characteristics and the thermodynamic properties of homologous substances. The focus of the present research is on the homologous series of n-alkyl benzenes. The analysis determined that the thermodynamic functions of substances additively depend on the molar weight of n-alkyl benzenes in the homologous series. Similar dependence was observed for the flash point of n-alkyl benzenes. Taking into account the fact that the flash point values and the Helmholtz energy tend to change depending on the molar weight of the substances in the homologous series, it seems practical to establish their interrelation. The corresponding equations were derived. Similar dependencies were previously observed for the homologous series of n-alkyletanoats, aliphatic ketones, n-alkylamines, and alcohols. The established regularities and proposed equations allow us to forecast the properties of homologous series of substances with sufficient accuracy.