Temperature effect and RDS

• what is the rate determining step?

  Slowest step in the multi-step reaction
• the rate equation only includes reacting species involved in the rate-determining step
• as temperature increases the rate increases and the rate constant value will also increase
• what factors affect the rate constant?

  -increasing the temperature shifts the boltzmann distribution to the right

  • larger proportion of molecules have energy greater than or equal to the activation energy
• affect of temperature on rate and rate constant

  increasing the temperature shifts the boltzmann distribution to the right

  • larger proportion of molecules have energy greater than or equal to the activation energy
  • as temperature increases, particles move faster and collide more frequently
• Arrhenius equation

  
• rate constant and the rate of reaction are directly proportional to the proportion of molecules with energy with energy equal to or greater than the activation energy
• intercept c of lnA on the y axis
• gradient m is -Ea/RT
• a plot of ln k against 1/T gives a straight line of y=mx + c
• • An increase in the activation energy means that the proportion of molecules which possess at least the activation energy is less
  • This means that the rate of the reaction, and therefore the value of k will decrease
• Graph of lnK against 1/T

  
• Arrhenius equation

  lnk = -Ea/RT + lnA

  y= mx + c
• A is the number of successful collisions with the correct orientation

  (explanation of A is not needed)