Which factors can affect reaction rate?

I.     The state of the reactants

II.     The frequency of the collisions between particles

III.     The average kinetic energy of the particles

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

D

The fact that the state of the reactants is inevitably linked to the frequency of collisions between particles appeared to cause a degree of confusion as to whether they were separate factors and as a result the question also proved a poor discriminator, with a discrimination index of 0.04. A decision was therefore taken to omit it from the total mark.