第三章理想气体的性质概述.pptVIP

2.混合气体的分容积和阿密盖特分容积定律Component Volume and Amagat’s law additive volume （1）Definition of component volume (分容积 的定义) 假定混合气体中组成气体具有与混合气体相同的温度及压力时，单独存在所占有的容积。 （2） Amagat’s law additive volume (阿密盖特分容积定律) 3. Composition of gas mixture (混合气体的成分) （1）质量成分（mass fraction） (2) 容积成分（volume fraction) (3) 摩尔成分 （mole fraction) (4) 质量成分、容积成分与摩尔成分间的换算关系 （relationship between mass fraction, volume fraction and mole fraction) 4. 混合气体的折合分子量与气体常数 Molar mass (Average mass ) and the gas constant （1）Molar mass (折合分子量) （2）Gas constant (折合气体常数) 5. 分压力的确定 Determine the Component pressure 6. 混合气体的比热 Specific heat of gas mixture * * * * * * * * * * * * * * * * * * * * * * * * For a constant temperature process, the addition or removal of heat will lead to a change in the volume and pressure of the gas, as shown on the two graphs above. Substitute into (1)过程方程 (Process equation) (2) 内能、焓及熵的变化量 The change in Internal Energy, Enthalpy and Entropy (3)功量和热量 Work Done and Heat Transferred In an isothermal process, the temperature is constant. Applying the first law of thermodynamics to this closed process For an ideal gas, the internal energy is a function of temperature only, and since the temperature is constant, then dU is zero and using the ideal gas law and integrating between the start and end of the process During an isothermal process, the work done by the system is equal to the heat added to the system, and all the work is technically usable. 4.绝热过程 Adiabatic Process (1) Process equation (过程方程) or Quasi-static, adiabatic process for an ideal gas δq = cvdT + pdv and δq = cpdT – vdp then cvdT = -pdv and cp dT =vdp therefore then finally, we arrive at the very useful expression from which it can also be shown that or When the temperatures at the start and end of the proces