Question

If Q > K, the sign of ∆G is .________

Adding an inert solute raises the boiling point because_______ it the entropy of the solution. If dissolving a salt in water evolves heat, solubility will_______ as temperature increases. Hydrocarbons have low solubility in water because the waters around the solutes become _____, decreasing the_____ .

Answer 1

1. We know, ∆G = ∆G° + RT ln Q (i)

and, ∆G° = -RT ln K (ii)

Substituting (ii) in (i): ∆G = RT ln Q/K

Now, Q/K will determine the sign of ∆G

If Q/K > 1, that is Q > K, then ∆G is positive, and the reaction is spontaneous in the opposite direction (proceeds towards reactants).

2. Increases

Adding solute molecules to the solution introduces new available microstates into the system and hence increase its entropy

3. Decrease

The question states that dissolution of salt is exothermic. According to Le Chatelier's Principle if the temperature is increased for an exothermic process then dissolution decreases and if the temperature is increased for an endothermic process then dissolution increases.

4. Hydrophobic molecules in water generally cluster together and so do the water molecules in turn minimizing their surface contact, and associated surface energy