a) The synthesize of ammonia from nitrogen and hydrogen gaseous endothermic reaction takes place as below: Ng (g) + 3H5(g) + NH4(g) 1) The equilibrium of a reaction varies depending on several factors such as pressure, temperature and initial number of moles for product and reactant. By using Le Chatelier's Principle, explain mechanism to control the equilibrium which occurs during a gas reaction. (6 marks)