Chemical industry plays an important role in the national economy of many countries, and it is the basic industry and pillar industry of many countries. However, due to various categories, complex processes and diverse products in the chemical industry, the pollutants discharged in production are various, large in quantity and highly toxic, and a large number of toxic substances may be produced in the process of product processing, storage, use and waste treatment, which may affect the ecological environment. Therefore, the chemical industry is a big polluter. Chemical industry is a double-edged sword, with advantages and disadvantages.

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1. Chemistry plays an important role in people's daily life and industrial and agricultural production. Chemistry has greatly promoted the development of industrial and agricultural production and enriched people's lives. Man can't live without chemistry. The significance of learning chemistry lies in meeting people's material needs, conducting chemical experiments and establishing chemical theories, and understanding the regularity of chemical changes. In the final analysis, it is to guide the production of material materials. To meet people's material needs, its purpose is to develop new energy, new materials and new technology, increase food production and improve health. The chemical industry plays such a role in industrial and agricultural production, such as sulfuric acid industry in the whole country.

It occupies an important position in the economy. Sulfuric acid industry is the foundation of many industrial sectors, and its output marks the developed degree of a country's industry to a certain extent; The role of synthetic ammonia industry in people's life and industrial and agricultural production is irreplaceable by other industries. Synthetic ammonia is the most important way for human beings to prepare nitrogen-containing compounds from nature.

3. The use is irreplaceable by other industries. Ammonia synthesis is the most important method to prepare nitrogen-containing compounds from nature, and ammonia is the most important raw material for further synthesis of nitrogen-containing compounds. Synthetic ammonia industry is the foundation of nitric acid industry, nitrate industry and chemical fertilizer industry, and its development will promote the development of other chemical industries. Chlor-alkali industry is one of the basic chemical industries, and its products, caustic soda and chlorine, occupy an important position in the national economy. The chemical fertilizer and pesticide industries have made great contributions to the development of agriculture, greatly promoting the increase of agricultural output and the development of new agricultural varieties.