Question

The surface of a soap film was increased isothermally by Δσ  at a temperature T. Knowing the surface tension of the soap water solution α and the temperature coefficient dα/dT, find the increment

(a) of the entropy of the film's surface layer;

(b) of the internal energy of the surface layer.

Answer 1

As before we can calculate the heat required. It, is taking into account two sides of the soap film