Which point on an energy diagram for the reaction A → D represents the transition state?

• A. The lowest point on the energy curve
• B. The starting point labeled A
• C. The highest point on the energy curve between A and D
• D. The ending point labeled D

Answer: (C)

Verified step by step guidance

1. Understand that an energy diagram for a chemical reaction plots the potential energy of the system as the reaction progresses from reactants to products.
2. Identify that the starting point labeled A represents the reactants, and the ending point labeled D represents the products, both corresponding to energy minima on the diagram.
3. Recognize that the transition state corresponds to the highest energy point along the reaction pathway, representing the energy barrier that must be overcome for the reaction to proceed.
4. Note that this highest point is located between the reactants (A) and products (D) on the energy curve, often depicted as a peak or hill.
5. Conclude that the transition state is represented by the highest point on the energy curve between A and D, not by the lowest points or the labeled start/end points.