Practice question · Numerical answer
A solid melts at 250 K with an enthalpy of fusion of 5.0 kJ/mol. Compute its entropy of fusion in J/mol/K.
Hints
- At the melting point the two phases are in equilibrium, so dG is zero.
- That makes dS = dH/T; compute 5000/250.
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20 (answers within ±0.5 count)
Why
At equilibrium , so J/mol/K. The positive value reflects the extra freedom a liquid has over a lattice.
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