A2 Kinetics

A2 Kinetics

Rate of Reaction: the change in concentration of reactants and products in a reaction per unit time
1. Units of Rate: moldm-3s-1
Order of Reaction: the power to which a species is raised to in the rate equation
1. 1st Order
  1. Rate is directly proportional to concentration of species
2. 2nd Order
  1. Rate is directly proportional to square of species concentration
3. 0 Order
  1. Species has no effect on rate
4. Overall order: all the orders in rate equation added together
Reactions often have multiple 'steps' as there are many ions/molecules so they are unlikely to all collide at once
1. Mechanism: separate steps leading from reactants to products
Rate Determining Step (RDS): the slowest step in the mechanism
1. Reaction is only as fast as its slowest step so the RDS determines overall rate
Determine K by:
1. Rate / [A][B]
A temperature increase leads to an increase in K
For a 1st order overall reaction the unit of k is s -1
1. For a 2nd order overall reaction the unit of k is mol-1dm3s -1
  1. For a 3rd order overall reaction the unit of k is mol-2dm6s -1

Resource summary

	Created by Emily Wordsworth over 9 years ago