Thermodynamic process(热力学过程):the operation(操作) of changing the system from its initial state(a) to its final state(b) is called a thermodynamic process as shown in above figure (Ph, Vh,T) 热力学过程 a b, b
The rmodynami c proc e ss(热力学过程):the operation(操作） of changing the system from its initial state(a) to its final state(b) is called a thermodynamic process as shown in above figure. ( , , ) Pa Va Ta ( , , ) Pb Vb Tb 热力学过程 P V a o b ( , , ) Pa Va Ta ( , , ) Pb Vb Tb
Equilibrium process平衡过程: In an equilibrium process, the system remains approximately in thermodynamic equilibrium at all stages, represented by a smooth curve on p-v diagram. (Pa,va, Ta) aQ(Pa, Va,T) (P,v,T) 和日目日日目口目日日口日日 ■日■■■ PV.T (P,o,T C O C C C Is a real process considered as equilibrium process?
( , , ) Pc Vc Tc V P o a c ( , , ) Pa Va Ta (P,V ,T) ( , , ) Pa Va Ta Equilibrium process平衡过程：In an equilibrium pro c e ss,the s y st em rema ins appro x ima t e l y in thermodynamic equilibrium at all stages, represented by a smooth curve on p-V diagram. Is a real process considered as Equilibrium process? ( , , ) Pc Vc Tc (P,V ,T)
3. The ideal gas law理想气体状态方程 For the ideal gas of mass M, its state parameters have a simple relationship M (V,PT P==RT(6-1 which is the equation of state of ideal gas, and holds for equilibrium state Here, R is a constant and has the same value for all gases, called ideal gas constant(理想气体普适常数): R=8.31J/molk in SI units u is mole mass
3. The ideal gas law 理想气体状态方程 RT M PV (6-1) which is the equation of state of ideal gas, and holds for equilibrium state. Here, R is a constant and has the same value for all gases ,called ideal gas constant(理想气体普适常数): is mole mass. For the ideal gas of mass M, its state parameters have a simple relationship R 8.31J/molK in SI units. (V,P,T)
Eq (6-1)can be rewritten as (V,PT PV=nRT n A the number of mole or P RT M P = 丿RT where p is density(密度) of gas
Eq.(6-1) can be rewritten as PV nRT or P RT M n the number of mole where is density（密度） of gas. RT P V M (V,P,T)
We now define an ideal gas as one for (V,PT which eq (6-1)holds for all pressure and temperature. PV= Mμ RT (6-1) For a fixed mass of an ideal gas, we have Py Pv Py cons tan t T or T
We now define an ideal gas as one for which Eq.(6-1) holds for all pressure and temperature. For a fixed mass of an ideal gas, we have cons t T PV tan or 2 2 2 1 1 1 T PV T PV (V,P,T) RT M PV (6-1)