Question

which factor can decrease the rate of a chemical reaction?
○ low activation energy
○ high pressure
○ low temperature
○ high concentration of enzyme

Explanation:

• Low activation energy: Low activation energy means reactions can occur more easily, so it increases reaction rate. Eliminate this option.
• High pressure: For reactions involving gases, high pressure increases the concentration of reactants, leading to a higher reaction rate. Eliminate this option.
• Low temperature: Lower temperature means particles have less kinetic energy, so they collide less frequently and with less energy, which decreases the reaction rate. This is a valid factor.
• High concentration of enzyme: Enzymes act as catalysts, and a higher enzyme concentration (in enzyme - catalyzed reactions) increases the reaction rate. Eliminate this option.

Answer:

C. low temperature (assuming the options are labeled A: low activation energy, B: high pressure, C: low temperature, D: high concentration of enzyme)