FACTORS AFFECTING CHEMICAL REACTIONS

• The mass of reactants is equal to the mass of products according to the law of conservation of mass
• Factors that affect the rate of chemical reactions

  Determine whether a chemical reaction is successful or unsuccessful
• Collision theory


  Explains how collision between reactant molecules may or may not result in a successful chemical reaction
• Conditions for effective collision

  • Colliding molecules should possess a minimum kinetic energy to start a reaction (activation energy)
  • Reactant molecules should be in correct orientation when they collide
• Catalyst


  A substance that can be added to a reaction to increase the reaction rate without getting consumed in the process
• Common factors that affect the rate of chemical reactions

  • Change in temperature
  • Reactant concentration
  • Particle size and surface
  • Use of catalysts
• Increase in temperature


  Typically increases the rate of reaction
• Presence of light


  Influences number of chemical reactions that lead to spoilage of foods
• Ethylene (ripening hormone)


  Plays a major role in the ripening process
• Presence of light


  Can increase the temperature causing products to undergo chemical reactions
• Three important ingredients for fire

  Energy (heat), Fuel, Oxygen
• Acid rain


  Causes trees to die, removes minerals and nutrients from soil, impacts ecosystems, causes corrosion of metals and deterioration of buildings
• Oxidation (corrosion)


  Direct chemical reaction of oxygen gas in atmosphere with metal surfaces forming metal oxide (rust)
• Increase in temperature


  Increases the rate of oxidation (corrosion) reaction
• Knowing the factors that affect the rate of chemical reactions will help understand the benefits and harm caused by some chemical reactions and why the rate of some chemical reactions need to be controlled