Which of the following is responsible for lowering the activation energy of a chemical reaction?

• A. Catalyst
• B. Reactant
• C. Product
• D. Solvent

Answer: (A)

Verified step by step guidance

1. Understand the concept of activation energy: Activation energy is the minimum energy required for a chemical reaction to occur. It is the energy barrier that reactants must overcome to transform into products.
2. Identify the role of a catalyst: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by providing an alternative reaction pathway with a lower activation energy.
3. Differentiate between the given options: Reactants are the starting materials in a chemical reaction, products are the substances formed as a result of the reaction, and solvents are substances that dissolve other materials to form a solution. None of these inherently lower activation energy.
4. Recognize that a catalyst does not alter the reactants or products but instead facilitates the reaction by lowering the activation energy, making it easier for the reaction to proceed.
5. Conclude that the correct answer is 'Catalyst' because it is the only option that directly affects the activation energy, thereby increasing the reaction rate without being consumed.