The bond enthalpy is the energy required to break a specific covalent bond in one mole of gaseous molecules. To estimate the enthalpy ΔHrxn of the reaction 2SF4(g) + O2(g) → 2OSF4(g), we can use average bond enthalpies. The estimated enthalpy change of the reaction is -492.1 kJ/mol.
Step-by-step explanation:
The bond enthalpy is the energy required to break a specific covalent bond in one mole of gaseous molecules. The bond energy for a diatomic molecule, Dx-y, is defined as the standard enthalpy change for the endothermic reaction: XY(g) → X(g) + Y(g). To estimate the enthalpy ΔHrxn of the reaction 2SF4(g) + O2(g) → 2OSF4(g), we can use average bond enthalpies.
First, we calculate the energy required to break the bonds on the reactants side: 4 x 460 kJ/mol = 1840 kJ/mol. Then, we calculate the energy released to form the bonds on the products side: 2 moles of H-H bonds (2x436.4 kJ/mol) and 1 mol of O=O bond (1x498.7 kJ/mol). The sum of these energies is 1840 kJ/mol - (2x436.4 kJ/mol) - (1x498.7 kJ/mol) = -492.1 kJ/mol. Therefore, the estimated enthalpy change of the reaction is -492.1 kJ/mol.