An exothermic reaction has an absolute activation energy of . The total thermodynamic heat released — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

Deploying the universal master relationship $\Delta H = E_{a(f)} - E_{a(b)}$. We insert the known values, taking special care with the negative exothermic sign: $-20 = 30 - E_{a(b)}$. Structurally rearranging to isolate the unknown precisely yields $E_{a(b)} = 30 - (-20) = 50 \text{ kJ mol}^{-1}$.