Which term describes the minimum amount of energy required to initiate a chemical reaction?

• A. Entropy
• B. Activation energy
• C. Enthalpy
• D. Free energy

Answer: (B)

Verified step by step guidance

1. Understand that the question asks for the term that describes the minimum energy needed to start a chemical reaction.
2. Recall that entropy refers to the measure of disorder or randomness in a system, which is not related to the energy required to start a reaction.
3. Recognize that enthalpy is the total heat content or energy change during a reaction, but it does not specifically describe the initial energy barrier.
4. Know that free energy (Gibbs free energy) indicates the spontaneity of a reaction, combining enthalpy and entropy effects, but it is not the minimum energy to initiate the reaction.
5. Identify that activation energy is the minimum amount of energy required to overcome the energy barrier and start the chemical reaction.