kinetics

• collision theory

  -states that for a chemical reaction reaction to take place the particles need to collide with each other in the correct orientation and with enough energy
• activation energy

  -the minimum amount of energy required to start a chemical reaction

  -exo - reactants are higher in energy than products

  -endo - reactants are lower in energy than products

  -Ea in endo us relatively larger than exo
• catalyst

  -a substance that increases the rate of reaction by providing a alternate pathway with a lower activation energy and is regenerated at the end of the reaction
• rate of reaction

  -a meausred change in conc of a substance in a given time

  =change in amount of reactants or products/time
• Maxwell-Boltzmann distribution curve

  The distribution of the molecular speeds of gas particles at a given temperature; as temperature increases, average speed increases and the distribution becomes wider and flatter.

  
• changes in temp - maxwell b

  -when temp of reaction mixture increases, particles gain more kinetic energy

  -causes particles to move faster resulting in more frequent collisions

  -more successful collisions - proportion possess Ea to cause a reaction

  -higher temps = curve to flatten and peak shifts to the right

  
• effect of temp on ROR

  -increasing temp = faster ror

  -particles have greater kinetic energy so move faster

  -more frequent, successful collisions
• effect of conc on ROR

  -more conc, greater number of particles

  -increased collision frequency and therefore increased ror

  
• effect of pressure on ROR

  -increased press means molecules have less space to in which they can move

  -effective collisions increases

  -increased collision frequence

  -increased ror

  
• homogenous catalyst

  same phase as reactants
• Heterogenous catalyst

  a catalyst whose phase is different from the reactants
• Catalysts On maxwell Boltzmann distribution

  Ea line shifts to the left to show higher proportion of molecules that have Ea

  
• rate of reaction

  a change in conc of a substance in a given time