Heating a reaction up increases the energy of the particles, and so causes them to react more [slowly/rapidly] with one another. Additionally, heat can have an effect on disturbing the of a reaction.
In the Haber Process the forward reaction is [exo/endo]thermic and the reverse is [exo/endo]thermic. This means that as nitrogen and hydrogen react with one another to form ammonia, heat is [absorbed/released], but as ammonia breaks up into hydrogen and nitrogen, heat is [absorbed/released]. According to Le Chatelier’s principle, when a system which is in equilibrium is disturbed, it will respond in such a way as to counteract the disturbance. So if heat is added to a system in the Haber Process, the [exo/endo]thermic [forward/reverse] reaction is favoured to [absorb/release] some of that heat and so [cool the system back down/heat the system back up]. Both the forward and reverse reactions occur at [lower/higher] rates than before the heat was added, due to the additional kinetic energy of all the particles, but the [forward/reverse] reaction will have been speeded up to a greater extent than the [forward/reverse] reaction. So for a while, the system will not be in as the [forward/reverse] reaction occurs more rapidly than the [forward/reverse] reaction. This will [in/de]crease the amount of ammonia present, and [in/de]crease the amount of hydrogen and nitrogen. After a while a new dynamic equilibrium is reached. The rates of forward and reverse reactions are again to one another, and the amounts of reactants and products will remain . However, compared to before the pressure was applied, there will now be [less/more] ammonia present at equilibrium. A new equilibrium constant, Kc, [higher than/lower than/the same as] that of the original equilibrium, is reached.