Excess entropy of a dilute ideal solution

Excess entropy of a dilute ideal solution Given equations [2.30] and [2.24], we can write  

This function, which does not contain any terms pertaining to the solvent either, is non null. Here, again, it is important to avoid confusing the representation of the ideal dilute solution with that of the perfect solution. 

Molar heat capacity of an ideal dilute solution at constant pressure 

If we neglect the variations of the enthalpy values with temperature (which is often acceptable within a reasonable temperature range), we have  

the excess heat capacity at constant pressure of dilute ideal solutions is practically non-existent, which means that - like perfect solutions - dilute ideal solutions obey Kopp s law of additivity given by relation [A.2.14] in Table A.2.1 from Appendix 2. 

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