To calculate the enthalpy change H during the polymerization process, the student needs to determine the enthalpy of the reactants and the enthalpy of the products, and then subtract the enthalpy of the reactants from the enthalpy of the products.H = H products - H reactants In this case, the reactants are ethylene C2H4 and the initiator benzoyl peroxide. The product is polyethylene.1. First, the student needs to find the standard enthalpy of formation Hf for each reactant and product involved in the reaction. These values can be found in standard thermodynamic tables or chemistry textbooks. For this example, let's assume the following values:Hf ethylene = +52.4 kJ/molHf benzoyl peroxide = -124.5 kJ/molHf polyethylene = -108.0 kJ/mol per ethylene unit 2. Next, the student needs to determine the stoichiometry of the reaction. For simplicity, let's assume that one mole of ethylene reacts with one mole of benzoyl peroxide to form one mole of polyethylene with one ethylene unit .3. Now, the student can calculate the enthalpy change for the reaction:H = H products - H reactants H = [1 mol * -108.0 kJ/mol ] - [1 mol * +52.4 kJ/mol + 1 mol * -124.5 kJ/mol ]H = -108.0 kJ - +52.4 kJ - 124.5 kJ H = -108.0 kJ + 72.1 kJH = -35.9 kJSo, the enthalpy change for the polymerization process is -35.9 kJ. This means that the reaction is exothermic, as heat is released during the formation of polyethylene from ethylene and benzoyl peroxide.