According to the local Huilife Education and Training Network, industrial synthetic ammonia is exothermic, because synthetic ammonia is an exothermic reaction. Synthetic ammonia refers to ammonia directly synthesized by nitrogen and hydrogen in the presence of catalyst at high temperature and high pressure, which is a basic inorganic chemical process. In modern chemical industry, ammonia is the main raw material for chemical fertilizer industry and basic organic chemical industry. Origin of development: German chemist F. Haber (1868- 1934) began to study the direct synthesis of ammonia with nitrogen and hydrogen from 1902. 1908 applied for a patent, that is, the "recycling method". On this basis, he continued his research and improved the synthesis at 1909, and the ammonia content reached more than 6. This is a direct synthesis method widely used in industry.