A solid organic compound Y dissolves in water. The energetic contributions for the dissolution are listed below.
Standard enthalpy contributions (kJ mol⁻¹):
• Disruption of crystal lattice: +30
• Reorganization of water: +8
• Formation of solute–solvent interactions: −12
Standard entropy contributions (J mol⁻¹ K⁻¹):
• Disruption of crystal lattice: +120
• Reorganization of water: +25
• Formation of solute–solvent interactions: −10
Answer the following questions. Show all work, express temperatures to the nearest kelvin, and include correct units throughout.
(a) Calculate the overall standard enthalpy change for the dissolution of compound Y.
(b) Calculate the overall standard entropy change for the dissolution. Express the result in J mol⁻¹ K⁻¹.
(c) Determine the minimum temperature (in °C) at which the dissolution of compound Y becomes spontaneous under standard conditions.
(d) Based on your answer to part (c), predict whether compound Y will dissolve spontaneously in pure water at 25 °C. Justify your prediction quantitatively.