CHEMICAL KINETICS

• Temperature


  At higher temperatures, reactant molecules have more kinetic energy, move faster, and collide more often and with greater energy
• Collision theory

  When two chemicals react, their molecules have to collide with each other (in a particular orientation) with sufficient energy for the reaction to take place
• Kinetic theory

  Increasing temperature means the molecules move faster
• Catalyst

  A substance that increases the rate of a chemical reaction without itself being consumed
• Catalyst

  • Catalysts increase the rate of a reaction by decreasing the activation energy of the reaction
  • Catalysts change the mechanism by which the process occurs
• Heterogeneous catalyst

  One that is present in a different phase as the reacting molecules
• Homogeneous catalyst

  One that is present in the same phase as the reacting molecules
• Zero order reaction

  The change in the concentration of the reactant produces no effect on the rate
• First order reaction


  Doubling the concentration causes the rate to double
• Second order reaction

  Doubling the concentration causes a quadruple increase in rate
• Half-life

  The time taken for the concentration of a reactant to drop to half its original value
• CHEMICAL KINETICS


  deals with the study of the rates of chemical reactions and factors affecting reaction rates
• KINETICS


  studies the rate at which chemical process occurs
• MEASURING REACTION RATE

  the speed at which the reactants disappear

  the speed at which the products appear
• REVERSIBLE REACTION


  as products accumulates, they can begin to turn back into reactants
• Concentration of Reactant

  rates of reaction can be determined by monitoring the change in concentration of either reactant or products as a function of time.
• Temperature

  at higher temperature, reactant molecules have more kinetic energy, move faster, and collide more often and with greater energy.
• CONCENTRATION AND REACTION RATES

  rates of reactions can be determined by monitoring the change in concentration of either reactants or products as function of time
• TEMPERATURE AND REACTION RATES

  as temperature increases, so does the reaction rate
• COLLISION MODEL

  in a chemical reaction, bonds are broken and new bonds are formed. molecules can only react if they collide with each other.
• FACTORS AFFECTING REACTION RATE

  Catalyst- speed reaction by changing mechanism
• SURFACE AREA

  more area for reactants to be in contact
• PRESSURE OF GASEOUS REACTANTS OR PRODUCT

  increased number of collision
• RATE LAW

  each reaction has its own equation that expresses its rate as a function of the concentration
• REVERSIBLE REACTION

  as products accumulates, they can begin to turn back into reactants
• ELEMENTARY REACTION


  always follow simple rate law