Question

Calculate the standard enthalpy change (in kJ/mol) for the following chemical reaction at 298 K:2SO2(g) + O2(g) → 2SO3(g)Given the standard enthalpies of formation (∆Hf°) at 298 K for SO2(g), O2(g), and SO3(g) are -296.8 kJ/mol, 0 kJ/mol, and -396.0 kJ/mol, respectively.

Answer 1

To calculate the standard enthalpy change for the given reaction, we can use the following equation:H =  Hf products  -  Hf reactants For the given reaction, we have:H = [2  Hf SO3  -  2  Hf SO2  + Hf O2  ]Now, we can plug in the given values for the standard enthalpies of formation:H = [2   -396.0 kJ/mol  -  2   -296.8 kJ/mol  + 0 kJ/mol ]H = [-792.0 kJ/mol -  -593.6 kJ/mol ]H = -198.4 kJ/molSo, the standard enthalpy change for the given reaction at 298 K is -198.4 kJ/mol.