Ammonia water: obtaining, formula, application

2024 Author: Angel Austin | [email protected]. Last modified: 2023-12-17 05:14

Colorless gas with a pungent odor ammonia NH₃ not only dissolves well in water with heat release. The substance actively interacts with H₂O molecules to form a weak alkali. The solution has received several names, one of them is ammonia water. The compound has amazing properties, which are the method of formation, composition and chemical reactions.

Formation of ammonium ion

The formula for ammonia water is NH₄OH. The substance contains the cation NH_4⁺, which is formed by non-metals - nitrogen and hydrogen. The N atoms in the ammonia molecule use only 3 of the 5 outer electrons to form covalent polar bonds, and one pair remains unclaimed. In a strongly polarized water molecule, hydrogen protons H⁺ are weakly bound to oxygen, one of them becomes a donor of a free electron pair of nitrogen (acceptor).

An ammonium ion is formed with one positive charge and a special type of weak covalent bond - donor-acceptor. In its size, charge, and some other features, it resemblespotassium cation and behaves like alkali metals. Chemically unusual, the compound reacts with acids and forms s alts of great practical importance. Names that reflect the features of obtaining and properties of the substance:

• ammonia water;
• ammonium hydroxide;
• ammonia hydrate;
• caustic ammonium.

Precautions

Care must be taken when working with ammonia and its derivatives. Important to remember:

1. Ammonia water has an unpleasant smell. The released gas irritates the mucous surface of the nasal cavity, eyes, causes coughing.
2. When ammonia is stored in loosely closed vials, ampoules release ammonia.
3. Can be detected without instruments, only by smell, even a small amount of gas in solution and air.
4. The ratio between molecules and cations in solution changes at different pH.
5. At a value of about 7, the concentration of toxic gas NH decreases +

Production of ammonium hydroxide. Physical properties

When ammonia dissolves in water, ammonia water is formed. The formula of this substance is NH₄OH, but in fact ions are present at the same time

NH₄⁺, OH^–, NH_{3 molecules} and H₂O. In the chemical reaction of ion exchange between ammonia and water, an equilibrium state is established. The process can be shownwith the help of a diagram in which oppositely directed arrows indicate the reversibility of phenomena.

In the laboratory, obtaining ammonia water is carried out in experiments with nitrogen-containing substances. When ammonia is mixed with water, a clear, colorless liquid is obtained. At high pressures, the solubility of the gas increases. Water releases more ammonia dissolved in it as the temperature rises. For industrial needs and agriculture on an industrial scale, a 25% substance is obtained by dissolving ammonia. The second method involves the use of the reaction of coke oven gas with water.

Chemical properties of ammonium hydroxide

When two liquids come into contact - ammonia water and hydrochloric acid - they are covered with puffs of white smoke. It consists of particles of the reaction product - ammonium chloride. With a volatile substance like hydrochloric acid, the reaction takes place right in the air.

Slightly alkaline ammonia hydrate chemical properties:

1. The substance reversibly dissociates in water to form an ammonium cation and a hydroxide ion.
2. In the presence of the NH ion₄⁺, a colorless solution of phenolphthalein turns crimson, as in alkalis.
3. A neutralization chemical reaction with acids leads to the formation of ammonium s alts and water: NH₄OH + HCl=NH₄Cl + H ₂O.
4. Ammonia water enters into ion exchange reactions with metal s alts, which correspond to weak bases, and water-insoluble hydroxide is formed:2NH₄OH + CuCl₂=2NH₄Cl + Cu(OH) ₂ (blue sediment).

Ammonia water: application in various sectors of the economy

Unusual substance is widely used in everyday life, agriculture, medicine, industry. Technical ammonia hydrate is used in agriculture, production of soda ash, dyes and other products. Liquid fertilizer contains nitrogen in a form easily digestible by plants. The substance is considered the cheapest and most effective for pre-sowing application for all crops.

The production of ammonia water costs three times less than the production of solid granular nitrogen fertilizers. Hermetically sealed steel tanks are used for storage and transportation of liquids. Some types of hair dyes and bleaches are made using caustic ammonium. Every medical institution has preparations with ammonia - a 10% ammonia solution.

Ammonium s alts: properties and practical value

Substances that are obtained by the interaction of ammonium hydroxide with acids are used in economic activities. S alts decompose when heated, dissolve in water, undergo hydrolysis. They enter into chemical reactions with alkalis and other substances. Ammonium chlorides, nitrates, sulfates, phosphates and carbonates of ammonium have acquired the most important practical value.

Veryit is important to follow the rules and safety measures when working with substances that contain the ammonium ion. When stored in warehouses of industrial and agricultural enterprises, in subsidiary farms, there should be no contact of such compounds with lime and alkalis. If the tightness of the packages is broken, a chemical reaction will begin with the release of toxic gas. Everyone who has to work with ammonia water and its s alts must know the basics of chemistry. Substances used will not harm people or the environment if safety requirements are met.