Question

Using standard enthalpies of formation, calculate the enthalpy change for the reduction of iron(III) oxide (Fe2O3) to iron metal (Fe).

Answer 1

To calculate the enthalpy change for the reduction of iron III  oxide  Fe2O3  to iron metal  Fe , we need to use the following equation:H_reaction =  H_f products  -  H_f reactants The balanced chemical equation for the reduction of iron III  oxide to iron metal is:Fe2O3 + 3CO  2Fe + 3CO2Now, we need the standard enthalpies of formation  H_f  for each substance involved in the reaction:H_f Fe2O3  = -824.2 kJ/molH_f CO  = -110.5 kJ/molH_f Fe  = 0 kJ/mol  since it's an element in its standard state H_f CO2  = -393.5 kJ/molNow, we can plug these values into the equation:H_reaction = [2H_f Fe  + 3H_f CO2 ] - [H_f Fe2O3  + 3H_f CO ]H_reaction = [2 0  + 3 -393.5 ] - [-824.2 + 3 -110.5 ]H_reaction = [-1180.5] - [-1155.7]H_reaction = -24.8 kJ/molSo, the enthalpy change for the reduction of iron III  oxide  Fe2O3  to iron metal  Fe  is -24.8 kJ/mol.