Question

Which of the following pairs of substances has the higher chemical potential (μ) under the specified conditions? They may be equal.

1.) H2O (s) at -1 degrees Celsius and 1 bar, or H2O (s) at 1 degrees Celsius and 1 bar

2.) H2O (g) at 100 degrees Celsius and 1 bar, or H2O (l) at 100 degrees Celsius and 1 bar

3.) H2O (g) at 105 degrees Celsius and 1 bar, or H2O (g) at 105 degrees Celsius and 2 bar

4.) H2O (g) at 95 degrees Celsius and 1 bar, or H2O (l) at 95 degrees Celsius and 1 bar

5.) KBr (s) in contact with unsaturated aqueous solution of KBr at 25 degrees Celsius and 1 bar

Answer 1

The substance with the higher chemical potential will tend to spontaneously turn into something else, e.g. in the first case ice at 1 C will tend to spontaneously turn into water, while ice at -1 C is stable.

That's a little oversimplified, but it should do for these questions.