Questions: O2 + O2 Reaction Coordinate O2 + O O + O E [kJ] What is the value of the activation energy for this reaction? Is this reaction exothermic or endothermic? What is the value of ΔE for the reaction?

Solution Steps

The activation energy (Ea) is the energy difference between the reactants and the highest point on the reaction coordinate diagram (the transition state). In this case, the energy of the reactants (O₃ + O) is lower than the energy of the products (O₂ + O₂). The difference in energy between the reactants and the transition state is 19 kJ.

An exothermic reaction releases energy, meaning the products have less energy than the reactants. An endothermic reaction absorbs energy, meaning the products have more energy than the reactants. In this diagram, the energy level of the products (O₂ + O₂) is lower than the energy level of the reactants (O₃ + O). Thus, the reaction is exothermic.

The change in energy (ΔE) is the difference in energy between the products and the reactants. ΔE can be calculated by subtracting the energy of reactants from the energy of products. Here, the energy level of reactants (O₃ + O) is 392 kJ, and the energy level of products (O₂ + O₂) is taken as 0kJ (assumed as the baseline). Thus, ΔE = 0 kJ - 392 kJ = -392 kJ.

Final Answer: