Which of the following would you predict to have a positive value for º?

AgCl (s) → Ag + (aq) + Cl - (aq)

H2O (g) → H2O (l)

2 Na (s) + Cl2 (g) → 2NaCl (s)

Br2 (l) → Br2 (s)

Given:

AgCl (s) = = = > Ag + (aq) + Cl - (aq)

- negative entropy

H2O (g) = = = > H2O (l)

- positive entropy

2Na (s) + Cl2 (g) = = = > 2NaCl (s)

- positive entropy

Br2 (l) = = = > Br2 (s)

-positive entropy

They are identified to have positive or negative values of entropy based on the phases of the reactants and products.