Question

Calculate the standard enthalpy change (ΔH°) for the following reaction at 298 K:2SO₂(g) + O₂(g) → 2SO₃(g)given the following standard enthalpy of formation values:ΔH°f (SO₂(g)) = -296.8 kJ/molΔH°f (O₂(g)) = 0 kJ/molΔH°f (SO₃(g)) = -395.7 kJ/mol

Answer 1

To calculate the standard enthalpy change  H  for the reaction, we can use the formula:H =  Hf  products  -  Hf  reactants For the given reaction:2SO g  + O g   2SO g The enthalpy change  H  can be calculated as follows:H = [2  Hf  SO g  ] - [2  Hf  SO g   + Hf  O g  ]Substitute the given values:H = [2   -395.7 kJ/mol ] - [2   -296.8 kJ/mol  + 0 kJ/mol]H =  -791.4 kJ  -  -593.6 kJ H = -197.8 kJThe standard enthalpy change  H  for the reaction is -197.8 kJ.