Absent pV work and heat exchange with the surroundings, the First law requires that the internal energy of the mixture be equal to the sum of the values of the pure components, or:
where u is the molar internal energy of component i and u is the internal energy per mole of mixture or solution. Because mixing occurs at constant pressure and there is no change in system volume, a similar equation applies to the enthalpy:
Since the specific heats CV and CP are temperature derivatives of u and h, respectively, the same mixing rules apply:
where CVi and CPi are the molar specific heats of pure component i.
The entropy of an ideal mixture or solution is not as transparent as are U and H. This issue is treated in Sect. 7.2.2
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Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.