State the symbol equation for the production of ammonia in the Haber process, ( N_2(g) + 3H_2(g) ightleftharpoons 2NH_3(g) )

Describe and explain the effect on the rate of reaction of: (a) changing the concentration of solutions (b) changing the pressure of gases (c) changing the surface area of solids (d) changing the temperature (e) adding or removing a catalyst, including enzymes using collision theory