Unit 15 Podcast: Factors Affecting Reaction Rates

Introduction

• Discussion of factors that can speed up reaction rates.
• Importance of speeding up reactions for efficiency.

Factors Affecting Reaction Rates

1. Concentration

• Increasing the concentration of solutions increases the chances of collisions, accelerating the reaction rate.
• Example: Higher concentration of acid corrodes metal faster.
• Case Study: Apollo 13 incident due to high oxygen concentration causing an explosion.

2. Surface Area

• Increased surface area leads to faster reactions.
• Example: Powdered sugar dissolves faster than sugar cubes.
• Case Study: Grain elevator explosions caused by increased surface area of powdered grain.
  • Moisture causes clumping, creating air pockets.
  • Sparks can ignite the grain due to increased surface area.

3. Temperature

• Increasing temperature raises kinetic energy, leading to more frequent collisions and faster reactions.
• Example: Bread dough takes longer to rise when frozen.

4. Catalysts

• Catalysts lower activation energy needed for reactions, speeding them up.
• Specific catalysts work for specific reactions, often using metals.
• Examples:
  • Catalytic Converters:
    • Used in cars to reduce pollution by converting NOx gases into safer nitrogen and oxygen.
    • Made with metals like palladium or platinum.
  • Enzymes:
    • Biological catalysts, e.g., digestive enzymes speeding up digestion.

Inhibitors

• Inhibitors increase activation energy, slowing down reactions.
• Used to prevent undesirable reactions, e.g., food preservatives.

Conclusion

• Overview of factors affecting reaction rates.
• Invitation for questions and reminder to complete podcast question.