Concentration & Pressure-

• The greater the frequency of successful collisions, the greater the rate of reaction
• If the concentration of a reacting solution or the pressure of a reacting gas is increased:

  • Reactant particles are closer together
  • The frequency of collisions between reactant particles increases
  • Therefore, the rate of reaction increases
• Note that the mean energy of the particles does not change
• Since the frequency of collisions increases (they happen more often), the frequency of successful collisions also increases