Question

Calculate the standard enthalpy and entropy change for the reaction that occurs when 1 mole of Fe2O3 is formed from its elements in their standard state, using the following given data:Fe(s) + 1.5 O2(g) → Fe2O3(s)    ΔH°f = -824.2 kJ/mol   ΔS° = 87.4 J/mol·K

Answer 1

We are given the standard enthalpy of formation  Hf  and the standard entropy change  S  for the formation of 1 mole of Fe2O3 from its elements in their standard state. The reaction is:Fe s  + 1.5 O2 g   Fe2O3 s We are asked to calculate the standard enthalpy change  H  and the standard entropy change  S  for this reaction.Since we are given the standard enthalpy of formation  Hf  for the reaction, we can directly use it as the standard enthalpy change  H  for the reaction:H = -824.2 kJ/molFor the standard entropy change  S , we are given the value directly as well:S = 87.4 J/molKSo, the standard enthalpy change  H  for the formation of 1 mole of Fe2O3 from its elements in their standard state is -824.2 kJ/mol, and the standard entropy change  S  is 87.4 J/molK.