5.  The reaction of solid calcium oxide with solid ammonium chloride is endothermic: 

CaO (s) + 2 NH₄Cl (s) ⇌ 2 NH₃ (g) + H₂O (g) + CaCl₂ (s)

a) Do you expect ΔS°_rxn to be positive or negative for this reaction? Explain your answer in 1-2 sentences.

b) Do you expect this reaction to be always spontaneous, never spontaneous, spontaneous only at high temperatures, or spontaneous only at low temperatures? Explain your answer in 1-2 sentences.

c) This reaction is carried out in a syringe and allowed to reach equilibrium. If the pressure inside the syringe is increased by decreasing the volume, which direction will the equilibrium shift? Explain your answer in 1-2 sentences.