Thermodynamic data for Gibbs energy of formation is shown below (kJ/mol for molal standard states) at 298.15 K. A saturated solution of NaCl is approximately an ideal solution.

(a) Use the Gibbs energy of formation to determine the solubility of NaCl in molality at 298.15 K. Treat the equilibrium between the solids and ions as a K_sp.

(b) Determine the NaCl solubility (molal) when the concentration of KCl is 1 m.

(c) Prove that the solution in part (b) is not saturated with KCl. (An ideal solution is actually a poor approximation for a saturated solution of KCl, but provide the proof based on an ideal solution.)

Transcribed Image Text:

KC1(s) -408.92 NaCl(s) -384.12 Cl(aq) -131.29 K+ (aq) -282.46 Na+ (aq) -261.88