Which of the following changes will increase the rate of reaction during combustion?

• A. Adding an inert gas to the reaction mixture
• B. Decreasing the temperature
• C. Increasing the concentration of oxygen
• D. Reducing the surface area of the fuel

Answer: (C)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on factors such as concentration of reactants, temperature, surface area, and presence of inert gases.
2. Recall that increasing the concentration of a reactant generally increases the rate of reaction because more reactant particles are available to collide and react.
3. Recognize that adding an inert gas at constant volume does not affect the concentration of reactants and therefore does not increase the reaction rate.
4. Know that decreasing the temperature reduces the kinetic energy of molecules, leading to fewer effective collisions and thus decreases the reaction rate.
5. Understand that reducing the surface area of the fuel decreases the area available for reaction, which lowers the reaction rate.