The value of ΔG° at 261.0 °C for the formation of phosphorous trichloride from its constituent elements, P₂ (g) + 3Cl₂ (g) → 2PCl₃ (g)
Is ________ kJ/mol. At 25.0 °C for this reaction, ΔH° is -720.5 kJ/mol, ΔG° is -642.9 kJ/mol, and ΔS° is -263.7 J/K.

Question

Quizplus · Accepted Answer

To find ΔG° at 261.0 °C, use the equation ΔG° = ΔH° - TΔS°. Convert 261.0 °C to Kelvin (534.15 K) and ΔS° to kJ (by dividing by 1000). Then, ΔG° = -720.5 kJ/mol - (534.15 K)(-0.2637 kJ/K/mol) = -579.6 kJ/mol.

The Value of ΔG° at 261