Question

which of the following factors does not alter the rate of reaction?
a. color
b. concentration
c. temperature
d. presence of a catalyst

Explanation:

• Concentration: According to the collision theory, when the concentration of reactants increases, the number of reactant particles per unit volume increases. This leads to more frequent collisions between particles, which can increase the reaction rate.
• Temperature: An increase in temperature provides more kinetic energy to the reactant particles. Particles move faster, collide more frequently, and a greater proportion of collisions have sufficient energy (activation energy) to result in a reaction. So, temperature affects the reaction rate.
• Presence of a catalyst: A catalyst provides an alternative reaction pathway with a lower activation energy. More reactant particles can then have collisions with enough energy to react, thus increasing the reaction rate.
• Color: The color of a substance is a physical property related to the absorption and reflection of light. It has no direct relation to the chemical reactivity or the factors (such as collision frequency, activation - energy requirements) that govern the rate of a chemical reaction.

Answer:

A. Color