1. The problem statement, all variables and given/known data Chemical hand warmers produce heat when they're removed form their airtight plastic wrappers. These hand warmers utilize the oxidation of iron to form iron oxide. Calculate standard change of enthalpy for reaction and compute how much heat is produced from a warmer containing 15.0g Fe? 2. Relevant equations Summation notation involving products and reactants to calculate standard enthalpy of change 3. The attempt at a solution [2(-824.2kj/mol)]-[4(0)+3(0)]= -16484.4kJ/mol iron oxide I used the stochiometric relationships of the equation of iron+oxygen---> iron oxide to convert grams to moles of iron to moles of iron oxide and used the predetermined standard change of enthalpy and I got -221kJ emitted but the correct answer is -111kJ emitted.