Given that S° = 131 J/Kmol for H₂(g), estimate the value of $\Delta$S° for the reaction

Question

Quizplus · Accepted Answer

Since we are given the value of standard entropy change, we can use the equation:
ΔG° = ΔH° - TΔS°
We know that at standard conditions, ΔG° = 0, so rearranging the above equation:
ΔS° = ΔH°/T
Therefore, ΔH° = ΔS° x T
Plugging in the values, we get:
ΔH° = 131 J/Kmol * 298 K = -39,038 J/mol = -39.04 kJ/mol
Since ΔH° is negative, the reaction is exothermic. Finally, we need to convert ΔH° to ΔF° using the relation:
ΔF° = ΔH° - TΔS°
Plugging in the values, we get:
ΔF° = -39,038 J/mol - 298 K * (-131 J/Kmol) = -0.298 kJ/mol = -298 J/mol = -298 J/Kmol
Rounding off to significant figures, we get:
ΔF° = -300 J/Kmol ≈ -262 J/K (Option C).

Given That S° = 131 J/Kmol for H2(g), Estimate the Value

Given That S° = 131 J/Kmol for H₂(g), Estimate the Value