Essay on chemistry in the kitchen 300 words

The chemistry in the kitchen is wonderful, and when you walk into the kitchen, the chemistry we are familiar with comes into view. 1. Inorganic matter 1. Rusty kitchen knives: A common phenomenon in the kitchen is that the newly bought kitchen knives are smooth and bright, and they will begin to rust after a few days, and they will no longer be bright after a long time.

This is because iron reacts with oxygen in the air in a humid environment to form iron oxide. In fact, rust is a loose oxide film, which cannot prevent the internal metal reaction at all, so after a long time, the rust will continue to increase, so we should do a good job of protecting the kitchen knife, and after use, wipe it clean and remove the rust in time. Iron oxide is a reddish-brown powder, commonly known as iron red, which is commonly used for lacquering and coatings.

The main component of hematite is iron oxide. It is a raw material for ironmaking. Iron oxide is insoluble in water and does not react with water.

However, iron oxide can react with acid to form iron salts, and the chemical equation for its reaction with hydrochloric acid is: one component of iron oxide reacts with six molecules of hydrochloric acid to form two molecules of ferric chloride and three molecules of water. (Ionic equation:

One mole of iron oxide and six moles of hydrogen ions react to produce two moles of iron ions and three moles of water); In addition, heating iron hydroxide can also generate iron oxide powder (two molecules of iron hydroxide are heated to form a component of iron oxide and trimolecular water) 2. Dense oxide film alumina: aluminum is the most abundant metal element in the earth's crust, but people discovered and prepared elemental aluminum relatively late, because the chemical properties of aluminum are relatively active. It is difficult to extract elemental aluminum from the compounds of aluminum, and many compounds of aluminum play an important role in human production and life.

Among them, alumina is insoluble in water, has a high melting point and is strong, so a very thin oxide film covering the surface of aluminum products can well protect the inner metal. Alumina is an important raw material for smelting aluminum, and it is also a good refractory material Active aluminum reacts with oxygen in the air to form alumina, and its chemical equation is that four-molecule aluminum and three-molecule oxygen react to form two-molecule alumina, and the density of alumina can protect the inner metal from continued oxidation. In fact, even if it is polished aluminum foil, a new oxide film will be formed in the air.

The melting point of alumina that makes up the film is 2050, so it is commonly used in the laboratory to manufacture refractory crucibles, refractory pipes and other high-temperature resistant experimental instruments. Although alumina is insoluble in water, it can be soluble in acid and strong alkali solutions, and the substances formed when it is dissolved in alkali are sodium metaaluminate and water, so alumina is an amphoteric oxide.