science gasses

• Rate of reaction


  The speed of a reaction
• Some chemical reactions are very fast while some are very slow
• Fast reactions


  • Explosions
• Slow reactions


  • Rusting
• Collision theory


  A way in which scientists explain how particles react
• Collision theory


  • Particles are described as spheres
  • Particles must possess a minimum kinetic energy (activation energy)
  • Particles must have a correct orientation when they collide
• Not all collisions between molecules result in the formation of products
• Effective collisions


  Collisions where the colliding molecules possess a minimum kinetic energy (activation energy) and have a correct orientation
• Factors affecting the rate of reaction

  1. Temperature

  2. Surface area of reactants

  3. Concentration of reactants

  4. Presence of a catalyst
• As temperature increases


  The rate of reaction increases
• Surface area


  The smaller the pieces, the larger the surface area, leading to more collisions and more chances of reactions
• Higher concentration of reactants


  More collisions and higher probability of reaction
• Catalyst


  A substance that changes the rate of reaction without being used up in the reaction
• Catalysts


  • They do not produce more products, the same amount of products are produced
  • They are used in industry to make products more easily, saving time and money
  • They reduce the need for higher temperatures, saving fuel and reducing pollution
• Catalysts


  • Nickel used in the production of margarine
  • Iron used in the production of ammonia