Final answer:
At 298 K for the reaction SO2(g) + O3(g) to form SO3(g) and O2(g), the Gibbs free energy change (ΔG°) is negative, indicating that the reaction is spontaneous. The thermal energy component TΔS° is less than the enthalpy change ΔH°, hence the correct answer is (a).
Step-by-step explanation:
The reaction in question is SO2(g) + O3(g) ⇌ SO3(g) + O2(g) with given thermodynamic parameters ΔH°298 = -242 kJ/mol and ΔS°298 = -25 J/(K⋅mol). To determine the sign of the Gibbs free energy change (ΔG°) at 298 K, we use the Gibbs free energy equation:
ΔG° = ΔH° - TΔS°
Substituting the given values at 298 K, we calculate:
ΔG° = (-242 kJ/mol) - (298 K)(-25 J/(K⋅mol))
ΔG° = (-242,000 J/mol) - (298 K)(-25 J/(K⋅mol))
ΔG° = (-242,000 J/mol) + 7450 J/mol
ΔG° = -234,550 J/mol or -234.55 kJ/mol
Since ΔG° < 0, the reaction is spontaneous at 298 K. The magnitude of TΔS° (7450 J/mol) is smaller than that of ΔH° (242,000 J/mol). Therefore, the correct answer is: a) ΔG°<0 and TΔS° is smaller in magnitude than ΔH°