All of the following are factors that affect the rate of a chemical reaction except:

• A. Temperature
• B. Concentration of reactants
• C. Color of the reactants
• D. Presence of a catalyst

Answer: (C)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on factors that influence how often and how effectively reactant particles collide.
2. Recognize that temperature affects reaction rate because increasing temperature increases particle energy and collision frequency.
3. Know that concentration of reactants affects reaction rate because higher concentration means more particles in a given volume, leading to more collisions.
4. Identify that the presence of a catalyst affects reaction rate by providing an alternative pathway with lower activation energy, speeding up the reaction.
5. Realize that the color of reactants does not inherently affect the reaction rate, as it is a physical property unrelated to collision frequency or energy.