Questions: What is the heat of reaction? kJ / mol Is the reaction exothermic or endothermic? Exothermic Can you determine the activation energy? Yes, it's kJ / mol Can you determine the activation energy of the reverse reaction? No.

Solution Steps

• The heat of reaction (ΔH) is the difference in energy between the reactants (A + B) and the products (C + D).
• From the energy diagram, the energy of A + B is approximately 100 kJ/mol, and the energy of C + D is approximately 200 kJ/mol.
• ΔH = Energy of products - Energy of reactants = 200 kJ/mol - 100 kJ/mol = 100 kJ/mol.

• A reaction is exothermic if it releases energy (ΔH < 0) and endothermic if it absorbs energy (ΔH > 0).
• Since ΔH = 100 kJ/mol (positive), the reaction is endothermic.

• The activation energy (Ea) is the energy difference between the reactants and the highest point on the energy diagram.
• From the energy diagram, the highest point is approximately 350 kJ/mol.
• Ea = Energy at the highest point - Energy of reactants = 350 kJ/mol - 100 kJ/mol = 250 kJ/mol.

Final Answer