Question

2. In the following, does S increase or decrease: a) A drop of ink spreading out when it is placed in water b) NaCl(s)  Na+(aq) + Cl-(aq) c) Steam condensing into drops on windows

3. For the reaction C(s, diamond)  C(s, graphite), G = -0.693 kcal/mol at 25oC. According to this information, do diamonds spontaneously turn into graphite? In light of your answer to part a, why can diamonds be kept unchanged for thousands of years?

Answer 1

a. Increase in surface area is accompanied by increase in entropy.

b. Dissociation increases number of entities, so entropy increases.

c. Gas to liquid conversion is accompanied by decrease in entropy.