PROPERTIES OF PURE SUBSTANCES
Pure substance
Vapour-Liquid-Solid Phase Equilibrium
Equation of State
Chemical analysis;the ratio of hydrogen and oxygen is 2:1
Gases can be pure when there is no change in phase
Has more than one phase but with same chemical composition
Fixed chemical composition Ex(water)
liquid air and gaseous air is not pure substance
the pressure remains constant when heat is transferred to water,but specific volume and temperature increase
working fluid(solid,liquid and gas)
Saturation:pressure and temperature are not independent properties
Temperature
Pressure
the temperature at which vaporization happens
the pressure effected by temperature is called "saturation pressure"
Saturation liquid
Copressed liquid
pressure is greater than the saturation pressure for given temperature
subcooled liquid
temerature is lower than saturation temperature of given pressure
Quality X
if liquid and vapor exisit simunatsously is defined by the ratio of mass of vapour to the total mass
Superheated vapour
when the vapour temperature greater than the saturation temperature
any equations that relates to pressure ,temperature and specific volume
Ideal gas equation PV=RT
at higher densities ,the ideal gas law cannot be applied
At very low density all gases and vapours become ideal gases