Question

Which of the following is true about the decomposition of ozone?

Options

• ΔH = −ve, ΔS = +ve and ΔG = +ve

• ΔH = +ve, ΔS = +ve and ΔG = −ve

• ΔH = −ve, ΔS = +ve and ΔG = −ve

• ΔH = +ve, ΔS = −ve and ΔG = +ve

Answer 1

ΔH = −ve, ΔS = +ve and ΔG = −ve

Explanation:

Reaction: 2O₃ → 3O₂

• ΔH = –ve → Exothermic (O₂ is more stable than O₃)
• ΔS = +ve → 2 moles gas → 3 moles gas (disorder increases)
• ΔG = –ve → Spontaneous at all temperatures (since ΔG = ΔH – TΔS = –ve – T(+ve) = always –ve)