上游充通大粤 SHANGHAI JIAO TONG UNIVERSITY To define the intensive properties of a system,we need VAR pieces of 8.3 Specifying a system information about T,P,xi To determine the composition of each phase in the system with C components,we must specify C-1 pieces of information Intensive properties VAR:total number of variables to be specified VAR=P(C-1)+2 C:components Variables in Temperature,Pressure,composition P:phase Not take account of following situations: •Amount of each phase .Surfaces or surface energy 98.3 Specifying a system To determine the composition of each phase in the system with C components, we must specify C-1 pieces of information Variables in Temperature, Pressure, composition To define the intensive properties of a system, we need VAR pieces of information about T, P, xi 9