TY CONF TI THE FIRST LAW OF THERMODYNAMICS AND ENTHALPY KW enthalpy KW first law of thermodynamics KW internal energy KW endothermic reactions KW exothermic reactions JO MODELING INFORMATION SYSTEMS AND TECHNOLOGIES – 2025 AU Skvorcova, E.I. AU Yagodkin, A.S. AU Ohrimenko, D.M. PY 2025 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov