What Is the Standard Enthalpy Change for the Decomposition of One

Multiple Choice

What is the standard enthalpy change for the decomposition of one mole of SO₃? 2SO₂ + O₂→ 2SO₃ ΔH°_rxn = -198 kJ/mol

A) 198 kJ/mol
B) -99.0 kJ/mol
C) 99.0 kJ/mol
D) 396 kJ/mol
E) -396 kJ/mol