Thermodynamics question. Could be simpler than it looks, but I am really stuck.

[Jasbraman]

Precisely what does the following equation, in which R is the gas constant, allow one to calculate?



ln x_s = -dH_f/R(T₀-T/TT₀)



I have no idea what this could be. I know what each part of the equation is (gas constant, change in enthalpy of formation, Freezing point depression etc.) I just don't know what it allows me to calculate...except that its the natural log of something. I think it has something to do with entropy, but I'm not sure. Any help would be much appreciated.

 

[presbyope]

Notation is ambiguous. Did you mean

<br /> \ln x_s = \frac{-dH_f}{R}\left(\frac{T_0-T}{TT_0}\right)<br />

in which case x_s is dimensionless?

 

[Jasbraman]

That is exactly what I meant, yes. I did not know you could put in equations like that. Anyway, I have to find out precisely what it allows me to calculate, but I have no idea.

 

[presbyope]

That is exactly what I meant, yes. I did not know you could put in equations like that. Anyway, I have to find out precisely what it allows me to calculate, but I have no idea.

Try this:
1. the expression with T can be rewritten as two terms
2. exponentiate

 

[presbyope]

That should give you something that looks a lot like something else you're familiar with :-/

 

[Jasbraman]

Oohhhhh yeeeah! Thanks for that!