Thermal capacities and polytropic processes

Abstract Herein, we analyse polytropic processes for an ideal gas within the wider concept of thermal capacity. To answer question whether capacity is a process, path, or state function, argue that it should be tentatively set as path function and if remains constant along corresponding process polytropic. Of all paths, there are only two—at volume pressure—for which capacities— C V ${C}_{P}$?> P —are functions, i.e. system properties. The discussions herein valuable both scientifically instructively because they shed light on issues in undergraduate curricula not addressed sufficient detail physics textbooks, even most advanced ones.