How to prepare phosphoric acid in laboratory and its characteristics

Laboratory how to prepare phosphoric acid and its characteristics

Phosphoric acid is an important inorganic acid, which is widely used in industry, agriculture and medicine. The preparation of phosphoric acid in the laboratory and the study of its characteristics are of great significance for the understanding of its chemical properties and practical applications. This article will discuss in detail the method of preparing phosphoric acid in the laboratory and its characteristics.

1. laboratory preparation of phosphoric acid

The following three methods are usually used to prepare phosphoric acid in the laboratory: wet, thermal and electrolytic.

1. wet method The wet process is one of the most commonly used methods for the preparation of phosphoric acid in the laboratory. The method produces phosphoric acid by reacting a phosphate salt with an acid. For example, calcium phosphate is reacted with hydrochloric acid to produce phosphoric acid, calcium chloride and water. The reaction equation is as follows: [ Ca3(PO4)2 6HCl → 3CaCl2 2H3PO4 2H_2O ] The advantages of this method are simple operation, mild reaction conditions, and suitable for small-scale preparation in the laboratory.

2. thermal method The thermal process is the preparation of phosphoric acid by heating a mixture of phosphate and carbon. For example, heating a mixture of calcium phosphate and carbon produces phosphoric acid and carbon monoxide at high temperatures. The reaction equation is as follows: [ Ca3(PO4)2 2C → 2CaO 2P 2H2O ] This method requires high temperature conditions and usually requires the use of a resistance furnace, so it is more complicated to operate in the laboratory.

3. electrolytic method Electrolysis is the production of phosphoric acid by electrolysis of a phosphate solution. When a phosphate solution is electrolyzed, phosphate ions are reduced to phosphoric acid at the cathode and oxygen is produced at the anode. The reaction equation is as follows: [ 2HPO4 ^{2-} 6H2O → 2H3PO4 6H_2 4OH ^- ] The advantage of this method is that the reaction conditions are mild, suitable for the precise control of the concentration and purity of the preparation of phosphoric acid in the laboratory.

2. phosphoric acid characteristics

The characteristics of phosphoric acid are mainly reflected in its physical and chemical properties.

1. Physical Properties Phosphoric acid is a colorless and transparent liquid with a strong pungent odor. It has a density of 1.80g/cm³, a melting point of 42.3°C and a boiling point of 158°C. Phosphoric acid is liquid at room temperature, but solidifies into a solid at low temperature.

2. Chemical Properties Phosphoric acid is a strong acid, with strong oxidation. It can react with most metals to produce the corresponding phosphate and hydrogen, the reaction equation is as follows: [ H3PO4 Zn → Zn(PO4)2 H2↑ ] Phosphoric acid can also react with alkaline oxides or hydroxides to form the corresponding phosphates, for example: [ H3PO4 NaOH → NaH2PO4 H2O ] The chemical properties of phosphoric acid make it widely used in industry and research.

3. phosphoric acid application

Phosphoric acid has important applications in many fields.

1. Industrial Applications Phosphoric acid is widely used in the manufacture of phosphate fertilizers, matches, fireworks and explosives. Phosphoric acid is also used in the electronics industry as an etchant for semiconductor materials.

2. Agricultural Applications Phosphoric acid is an important raw material of phosphate fertilizer, which can promote the growth and development of plants and increase crop yield.

3. Medical applications Phosphoric acid is used in medicine to produce antibiotics, vitamins and anticoagulants. For example, chloroquine phosphate is an antimalarial drug, and phosphodiesterase inhibitors are used to treat cardiovascular disease.

4. conclusion

How to prepare phosphoric acid in the laboratory and its characteristics are important topics in chemical research. Through wet, thermal and electrolytic methods, the laboratory can prepare phosphoric acid of different concentrations and purities. The physical and chemical properties of phosphoric acid make it widely used in industry, agriculture and medicine. With the progress of science and technology, the research and application of phosphoric acid will be more extensive, and make greater contributions to the development of human society.

Through the introduction of this article, we have a comprehensive understanding of how to prepare phosphoric acid in the laboratory and its characteristics. It is hoped that this paper can provide valuable reference for researchers and students in related fields.