A certain salt dissolves in water at 298 K with a measured standard enthalpy change…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
A certain salt dissolves in water at 298 K with a measured standard enthalpy change of +3.9 kJ mol⁻¹. The experimentally determined standard free energy change for the process at the same temperature is −9.4 kJ mol⁻¹.
Respond to the prompts below. Clearly label your final answers with appropriate units.
(a) Determine the standard entropy change for the dissolution. Report the result in J mol⁻¹ K⁻¹.
(b) Discuss briefly—without further calculation—whether the sign and magnitude of the entropy change are consistent with the experimental observation that the salt dissolves readily at room temperature.