A key reaction in the upper atmosphere is O31g2 + O1g2 ¡ 2 O21g2 For this process, the energy of activation for the forward reaction, Ea1fwd2, is 19 kJ/mol, and the enthalpy change for the reaction, ΔHrxn, is -392 kJ>mol. What is the energy of activation for the reverse reaction, Ea1reverse2? (LO 14.10) (a) 411 kJ/mol (b) 392 kJ/mol (c) 373 kJ/mol (d) 196 kJ/mol

Verified step by step guidance

1. Identify the given values: the activation energy for the forward reaction, \( E_{a, \text{fwd}} = 19 \text{ kJ/mol} \), and the enthalpy change for the reaction, \( \Delta H_{\text{rxn}} = -392 \text{ kJ/mol} \).
2. Recall the relationship between the activation energies of the forward and reverse reactions: \( E_{a, \text{reverse}} = E_{a, \text{fwd}} + \Delta H_{\text{rxn}} \).
3. Substitute the given values into the equation: \( E_{a, \text{reverse}} = 19 \text{ kJ/mol} + (-392 \text{ kJ/mol}) \).
4. Simplify the expression to find \( E_{a, \text{reverse}} \).
5. Compare the calculated \( E_{a, \text{reverse}} \) with the provided options to determine the correct answer.

Key Concepts

Activation Energy

Activation energy (Ea) is the minimum energy required for a chemical reaction to occur. It represents the energy barrier that reactants must overcome to transform into products. In this context, the forward reaction has a specific activation energy, which is crucial for understanding how the reaction proceeds and how it can be influenced by temperature and catalysts.

Enthalpy Change (ΔH)

Enthalpy change (ΔH) is the heat content change during a chemical reaction at constant pressure. A negative ΔH indicates that the reaction is exothermic, meaning it releases energy. This value is essential for calculating the activation energy of the reverse reaction, as it helps determine the energy difference between reactants and products.

Energy Profile Diagram

An energy profile diagram visually represents the energy changes during a chemical reaction, showing the energy of reactants, products, and the activation energies for both forward and reverse reactions. Understanding this diagram helps in calculating the activation energy for the reverse reaction by using the relationship between the activation energies and the enthalpy change of the reaction.