Ineed with ammonia is an important ingredient in many fertilizers. the main process by which ammonia is made is the haber process. in this process, nitrogen gas and hydrogen gas are reacted to form ammonia at high temperatures. which of the following most likely explains why this reaction is carried out at high temperature? ammonia is unstable at room temperature. high temperatures increase the activation energy of the reaction. high temperatures make the gas molecules move more quickly. the reaction becomes exothermic at high temperatures.