Question

Consider the $\Delta$Gŗƒ and DHŗƒ (kJ/mol) for the following oxides. Which oxide can be most easily decomposed to form the metal and oxygen gas ?

• A. ZnO ($\Delta$G⁰ = –318.4, $\Delta$H⁰ = –348.3)
• B. Cu2O ($\Delta$G⁰ = –146.0, $\Delta$H⁰ = –168.8)
• C. HgO ($\Delta$G⁰ = –58.5, $\Delta$H⁰ = –90.8)
• D. PbO ($\Delta$Gŗ = –187.9, $\Delta$Hŗ = –217.3)

Answer 1

Answer: (C)

HgO ($\Delta$G⁰ = –58.5, $\Delta$H⁰ = –90.8)

Answer 2

Lesser the $\Delta$Gŗf, lesser its stability & easily it can

decompose.