The Collision Theory

• Collision theory explains how collision between reactant molecules may or may not result in a successful chemical reaction.
• Factors affecting the rate of chemical reaction  

  • Temperature
  • Surface area of reactants
  • Catalyst
  • Concentration of reactants
• The colliding molecules should possess a minimum kinetic energy known as activation energy to start a chemical reaction.
• Activation energy is needed to break the bond between reactant molecules to form new bonds leading to formation of the products.
• The reactants molecules should be in correct orientation when they collide.
• Temperature - increasing the temperature, increases the rate of chemical reaction. The higher the temperature, the higher kinetic energy of particles, the more they collide.
• Surface area of reactants - the smaller the size of particle, the greater the surface area. Increasing the surface area speeds up the rate of reaction by increasing the collisions rate.
• Catalyst is a substance that increases the rate of reaction.
• Inhibitor is a substance that slows down or inhibits reaction rates.
• Concentration of reactants - increasing the concentration of reactants, increases the rate of reaction. The more particles present, the more often they collide.
• Acid rain - caused by nitrogen oxide and sulfur dioxide produces by both natural processes and combustion of fossil fuels. This oxide reacts with oxygen and water to give nitric acid and sulfur acid.
• Formation of ozone layer in the atmosphere begins with the photolysis of oxygen molecule by solar radiation of wavelength below 240 mm.
• Car airbag - inside the airbag is gas generator containing a mixture of sodium oxide, when the car undergoes ahead in a collision, series of three chemical reaction inside the gas generator produces gas to fill the airbag and convert NAN3 which is highly toxic.
• Photochemical smug is a type of air pollution that happens when primary pollutants such as nitrogen oxide and volatile organic compounds reacts with O2 and ozone under the influence of sunlight.
• Fire control - various materials acts as fuel to sustain for different five prevention and control measure are recommended for ordinary combustible, flammable liquid or gases, electrical equipment and flammable metals.
• Corrosion control is a natural process which can convert a refined metal to a more chemically stable forms such as its oxide, hydroxide, or sulfide. Is a gradual destruction of materials by chemical or electromechanical reaction with their environment.