Question

Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.

Answer 1

Entropy is positive as liquids have greater disorder in terms of arrangement than that of solid ( use your entropy explanation for this) the Gibbs free energy change is positive as the reaction is spontaneous

Answer 2

When a crystalline solid dissolves, it becomes more disordered. When disorder increases, delta S is positive. This process probably has a positive delta S. The process is spontaneous. Spontaneous processes have delta G < 0; the process has a negative delta G