To calculate the enthalpy change for the oxidation of 25 grams of iron to form iron III oxide, we need to follow these steps:1. Write the balanced chemical equation for the reaction.2. Determine the moles of iron and iron III oxide involved in the reaction.3. Use the enthalpy of formation values to calculate the enthalpy change.Step 1: Balanced chemical equationThe balanced chemical equation for the oxidation of iron to form iron III oxide is:4 Fe s + 3 O2 g 2 Fe2O3 s Step 2: Determine the moles of iron and iron III oxideFirst, we need to determine the moles of iron Fe in 25 grams. The molar mass of iron is 55.85 g/mol.moles of Fe = mass of Fe / molar mass of Femoles of Fe = 25 g / 55.85 g/molmoles of Fe = 0.4476 molFrom the balanced chemical equation, we can see that 4 moles of Fe produce 2 moles of Fe2O3. Therefore, we can determine the moles of Fe2O3 produced by the reaction:moles of Fe2O3 = moles of Fe / 4 2moles of Fe2O3 = 0.4476 mol / 4 2moles of Fe2O3 = 0.2238 molStep 3: Calculate the enthalpy changeNow, we can use the enthalpy of formation values for Fe s and Fe2O3 s to calculate the enthalpy change for the reaction. The enthalpy of formation for Fe s is 0 kJ/mol, and for Fe2O3 s is -824.2 kJ/mol.H = [moles of products enthalpy of formation of products] - [moles of reactants enthalpy of formation of reactants]H = [ 0.2238 mol -824.2 kJ/mol - 0.4476 mol 0 kJ/mol ]H = -184.3 kJThe enthalpy change for the oxidation of 25 grams of iron to form iron III oxide is -184.3 kJ. The negative sign indicates that the reaction is exothermic, meaning it releases heat.