#3.2.2a
the effect of concentration, including the pressure of gases, on the rate of a reaction, in terms of frequency of collisions
#3.2.2b
calculation of reaction rate from the gradients of graphs measuring how a physical quantity changes with time
Suitable physical quantities to monitor could include concentration, gas volume, mass, etc.
#3.2.2c
explanation of the role of a catalyst:
(i) in increasing reaction rate without being used up by the overall reaction
(ii) in allowing a reaction to proceed via a different route with lower activation energy, as shown by enthalpy profile diagrams
Details of processes are not required.
#3.2.2d
(i) explanation of the terms homogeneous and heterogeneous catalysts
(ii) explanation that catalysts have great economic importance and benefits for increased sustainability by lowering temperatures and reducing energy demand from combustion of fossil fuels with resulting reduction in CO2 emissions
#3.2.2e
the techniques and procedures used to investigate reaction rates including the measurement of mass, gas volumes and time
PAG9
#3.2.2f
qualitative explanation of the Boltzmann distribution and its relationship with activation energy (see also 3.2.1c)
#3.2.2g
explanation, using Boltzmann distributions, of the qualitative effect on the proportion of molecules exceeding the activation energy and hence the reaction rate, for:
(i) temperature changes
(ii) catalytic behaviour (see also 3.2.2c).