CHEM 1202 Chapter : Chapter 5
Document Summary
Real gases tend to heat up as they are compressed. Some of the e added to gas as work escapes as heat. Work = e added to system by moving a barrier. Work energy moves in same direction as barrier. Heat = e added to system by penetrating through a barrier. Heat moves from hot side to cold side. Enthalpy (h) used to be called heat content. Enthalpy is a measure of the relative amount of heat energy a substance is capable of generating. Amount of heat absorbed by a process is final minus initial enthalpy of process components if no pressure change occurs. Enthalpy does not correctly calculate heat if after pressure is different than before pressure. Enthalpy is state function so it is ok if pressure changes during process as long as it goes back to original value when process complete.
