Acids have a wide range of applications and play important roles in many fields. Firstly, acidic substances are one of the essential compounds for maintaining normal metabolism and function in the human body; Secondly, it can play an important role as a chemical reagent in various experimental works such as reactions, synthesis, and separation techniques; Furthermore, it is also a basic chemical raw material for manufacturing industry, such as being used to produce inorganic salts, plastics, rubber products, and so on. In addition, it is also crucial to use it in certain specific environments or situations: for example, sulfuric acid is needed in water treatment processes to remove calcium and magnesium ions and protect equipment from corrosion; Metal surfaces can oxidize and corrode, leading to heavy metal pollution of soil and water sources. Hydrochloric acid can be used for cleaning and removal, and the polluted environment can be treated and restored; Plant nutrient regulator - potassium dihydrogen phosphate can promote the development and robustness of fruit tree roots, and has a better effect on fruit swelling and sweetness. It is non-toxic and does not harm natural enemies, and has a significant effect on improving fruit quality and safety in cold winter. Organic phosphorus farmers can use 2% glyphosate to remove weeds and carpet spray the affected crops to solve the problem. In short, both personal life and enterprise applications cannot do without the participation and cooperation of acid, which covers a wide range of needs and various aspects. With the advancement of technology, it is even more indispensable. However, it is necessary to choose the appropriate concentration and usage method correctly in order to better play its role and avoid unnecessary losses!