Kinetics

HideShow resource information
  • Created by: amy_br0
  • Created on: 08-05-14 18:58

Increasing Reaction Rate

rate of reaction ~ amount of substance produced per second 

FIVE WAYS OF INCREASING RATE:

  • increase surface area = more particles exposed = greater collision frequency
  • increase concentration = particles closer togethergreater collision frequency
  • increase temperature = particles have more energy, move faster = greater collision frequency + more successful collisions = double effect on rate of reaction 
  • add a catalyst = lower activation energy = more successful collsions
  • increase pressure = has to involved gases = same effect as concentration
1 of 3

Maxwell-Boltzmann Distribution

a graph showing the distribution of molecular energies in a gas

  • x-axis labelled "energy", y-axis labelled "number of molecules"
  • area under curve gives total number of particles in sample
  • starts at (0,0) because there no molecules with zero energy 

Increasing temperature:

  • lowers peak of the curve
  • shifts distribution to the right ~ more molecules with higher energies

Decreasing Temperature:

  • raises the peak
  • shifts the distribution to the left ~ less molecules with energy greater than activation energy


2 of 3

Catalysts

definition - a substance that increases the rate of reaction without going under any permanent change 

  • in terms of Maxwell-Boltzmann distribution ~ lowering activation energy= more molecules have a energy greater than activation energy = so more collisions will be successful = rate will increase
  • Catalyst do NOT appear in the equation for a reaction ~ written on top of arrow
3 of 3

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Kinetics resources »