2. OBJECTIVES : 1- know the pure substances 2- the phase changing 3- how to simulate the behavior by studying the “ properties ” by : a) graphs [(T-V),(P-V),(T-P),(P-v-T)] b) Tables c) Equations 4- know some IMP. Properties in our course [enthalpy, internal energy, specific volume, quality, latent heat ]

3. PURE SUBSTANCE A substance that has a fixed chemical composition throughout is called a pure substance. Water, nitrogen, helium, and carbon dioxide, for example, are all pure substances. Liquefied air : is not pure substance Ice, water, vapor : pure substance

5. Graphs

13. Enthalpy ??? Quality ???? Specific volume ??????? Internal energy ???? Tables : why?? Accurate, complex,

14. *Critical points *specific heat *[internal energy – enthalpy – entropy - specific volume] against [saturated – compressed - superheated] (T-P) for water and vapor

15. Relations & Equations Water is ideal ???????? It depends !!! Every sub. To it’s CRITICAL CONDITIONS

16. IF NOT ideal SO WHAT ???

17. THE PRINCIPAL OF CORRESPONDING THE STATES Every sub. Relative to it’s critical and characteristic conditions; so all will have the same chance of idealism and the deviation. Meanwhile they have diff. conditions, but the same state (“2yyyy”)

20. THANKS a lot !!!