Step 2: Write and balance the chemical equation.
a) Read the word equation: "Propane gas plus oxygen gas produces
b) Convert the word equation to a chemical equation and complete the reaction. Be sure to balance
the chemical equation.
c) Record the balanced chemical equation on the Student Worksheet.
Step 3: Determine the amount of energy change in the reaction.
a) Use the table of enthalpy values (Table A) provided in the Student Worksheet to locate the
enthalpy of formation (AH) for each reactant and each product. Record these values along with
the reactants and products in Table B of the Student Worksheet.
b) Determine the total enthalpy of the reactants and the total enthalpy of the products. Record these
values in Table C of the Student Worksheet.
c) Use the following formula to find the net change in enthalpy for the reaction and to determine
whether the reaction is endothermic or exothermic.
AH xn = (AH, products) - (AH, reactants)
Record your answers in Table D.
Step 4: Model the energy change in the reaction.
a) Create an energy graph that illustrates the energy change in the reaction.
b) Construct your graph on a blank sheet of paper. Be sure to label the axes, provide a title, and
identify the reactants and products on the graph.
Step 5: Explain the energy change in the reaction.