Thermodynamics - dependence of molar fraction on temperature

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The molar fraction of a solution does depend on temperature, contrary to some misconceptions. When a solution is heated, substances with different evaporation rates can alter the proportions of the components in the gas phase. By knowing the initial composition, enthalpies of evaporation, and the partial pressures after heating, Raoult's law can be applied to determine the new composition. This highlights the importance of temperature in influencing the behavior of solutions. Understanding these principles is crucial for accurate predictions in chemical processes.
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Why does the molar fraction of a solution not depend on temperature?

In other words, why will heating a solution preserve its composition? It seems to me that if I have two substances that evaporate at different rates, the substance with the faster evaporation rate will pass more moles into the gas phase, so the proportions of the substances in the solution should not be preserved.
 
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After thinking about it more, I actually found that the molar fraction does depend on the temperature (funny, because another online source mislead me by stating that it does not depend on the temperature).

If you know the initial composition, the enthalpies of evaporation for each substance and you know the quotient of the partial pressures after heating you can use Raoult's law to find the composition after heating.
 

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