Ammonia water is an aqueous solution of ammonia dissolved in water. Due to the complexity of its components, ammonia water shows diversity in its properties.

1. Diversity of components: ammonia water contains three molecules: ammonia monohydrate, water and ammonia; Three ions: ammonium ion, hydroxide ion, hydrogen ion. That's because most of it reacts with water to form ammonia monohydrate.

2. Particularity of smell: ammonia water has a special strong irritating odor, which can cause cough, shortness of breath and asthma after inhalation. Ammonia in the eyes can cause serious damage and even blindness; Burns can occur on skin contact, so be careful when using ammonia.

3. Volatile: ammonia is volatile, so the storage of ammonia should be sealed and placed in a cold place.

4. Particularity of density change: the density of ammonia water is less than 1. The thickest ammonia water contains 35.28% ammonia, and the density is 0.88g/cm3. In ammonia water, the more ammonia there is, the less dense it is. For example, when the mass fraction of ammonia water is 10%, the density is 0.958g/cm3, and when the mass fraction of ammonia water is 30%, the density is 0.892g/cm3.

5. Instability: -- ammonia hydrate is unstable, easy to decompose when exposed to light and generate ammonia and water.

In the laboratory, ammonia can be produced by heating concentrated ammonia water or by mixing concentrated ammonia water and solid caustic soda at room temperature. The device and operation are simple, and the ammonia concentration obtained is large, so it can be used as "fountain" experiment. Because ammonia is volatile and unstable, it should be sealed and stored in a brown or dark reagent bottle in a cold dark place.

6. Weak alkalinity: Ammonia hydrate in ammonia water can ionize OH-, so ammonia water shows weak alkalinity and has the common of alkali:

On the one hand, the colorless phenolphthalein test solution turned red, the purple litmus test solution turned blue, and the wet red litmus test paper turned blue. This method is commonly used in laboratories to test for the presence of NH3.

On the other hand, it can react with acids to form ammonium salts. White smoke is produced when concentrated ammonia water meets volatile acids such as concentrated hydrochloric and nitric acids. (This method can be used in the laboratory to check the presence of ammonia and ammonia)

In case of non-volatile acid (such as sulfuric acid, phosphoric acid) without this phenomenon. In industry, the weak alkalinity of ammonia is used to absorb the tail gas of sulfuric acid industry to prevent environmental pollution.

7. Precipitation: ammonia water is a good precipitator, it can react with a variety of metal ions, the formation of insoluble weak base or amphoteric hydroxide.

Al(OH)3 precipitation is insoluble in excess ammonia. Using this property, Al(OH)3 and so on can be prepared experimentally.

8. Complexation: ammonia and Ag+, Cu2+, Zn2+ ions can have complexation reaction. When ammonia is small, insoluble weak base or amphoteric hydroxide will be produced. This reaction is used in the laboratory to prepare solutions of silver ammonia.

9. Weak reducibility: Because the nitrogen element of ammonia water is in the lowest state, ammonia water shows weak reducibility and can be oxidized by a strong oxidant. For example, ammonia can react with Cl2

10. Liquid fertilizer: Ammonia is widely used in rural areas because it can be directly applied to farmland as fertilizer and is easily absorbed by crops after being applied to soil.