Reagents are substances without which chemistry can not be studied

Any section of chemistry involves the use of certain chemicals. Considering the fact that reagents are substances that can cause serious damage to human health, certain requirements are imposed on their storage.

7th group

Chemical reagents of this group have an increased toxicity, so there are certain requirements for their placement. They are in a special safe located in the laboratory. The key is from the assistant, and also from the teacher of chemistry.

In the educational schools the storage of chemical reagents is prohibited, and in the laboratories of higher educational institutions their presence is allowed only if there is a special order from the head of the educational institution. The laboratory assistant keeps a strict account of the expenditure of such substances, making notes in a special journal.

List of inorganic reagents allowed in the school laboratory

Let's list those basic inorganic chemical reagents that are allowed for demonstration experiments in chemistry lessons at school:

• Simple substances: metallic sodium, crystalline iodine, liquid bromine;
• Caustic soda, oxides of metals and non-metals;
• Salts, including complex compounds, dichromates and chromates;
• Solutions of acids.

Organic substances

Let's note organic reagents and substances that a chemistry teacher can use to create practical skills for students:

• aniline;
• Organic acids;
• benzene;
• phenol;
• formalin.

Requirements for safe for reagents

The safe installed in the laboratory chemistry, intended for storage of the reagents of Group 7, is most often made of solid sheets of metal. It is also possible to install a wooden structure, if the outside is safe with iron, the thickness of which will be not less than 1 mm.

There are also requirements for the location of the safe. Considering that reagents are sources of increased danger, it is necessary to choose such a place as a safe so that it can easily be taken out in the event of a fire.

A typical list of substances with high physiological activity

Among the reagents that have similar properties, mention may be made of metallic zinc, calcium, lithium, calcium oxide and hydroxide , metal nitrates , potassium iodide , potassium permanganate, zinc compounds. Such reagents are substances of increased danger, so experiments with them are allowed only under the direct supervision of the teacher.

Also listed are organic substances such as diethyl ether, acetone, alcohols, cyclohexane, chloroform, crude oil. Such reagents are substances having an effect on the human nervous system, therefore they are excluded from the list of chemical preparations used in ordinary educational schools for practical work and laboratory experiments.

In the class, only 8 groups of reagents are allowed to be placed (under lock and key), which are used during practical work and laboratory experiments. Such reagents are substances that are safe for children's health. For example, a solution of sodium chloride , potassium sulfate , calcium chloride.

Storage rules for small schools

In small rural schools that do not presuppose the availability of a special area for a laboratory room, the storage of chemical reagents should be given special attention. For example, an acid reagent in which the concentration of the active substance exceeds 50 percent should be placed in a closed and tied polyethylene bag.

Alkalis, which are in a solid aggregate state, must be at a considerable distance from acids, with the mandatory preservation of factory packaging. The opened bottle with caustic soda or potassium should be tightly closed, then placed in a plastic bag or jar, which is tightly closed with a stopper.

Only an aqueous solution of ammonia and hydrochloric acid has a high vapor pressure, so it is important to check the tightness of their packaging. As additional safety measures when working with such reagents, use of additional sealing plugs, plastic bags on the jar is considered.

In the absence of a place for separate placement of 2.5.6 groups of reagents, their joint arrangement in one cabinet is allowed. In this case, a separate shelf must be assigned to each group. The best option would be placing on the top shelf of the reagents of group 5, below you can put the banks with substances of group 6, in the lower part of the cabinet to put the reagents of group 2.

Conclusion

In any educational institution in which it is intended to use chemical reagents for lessons and extracurricular activities, there is a special instruction according to which a certain space is allocated for them. Classical laboratory sectional cabinets used for the placement of chemical reagents are lined with modern polymeric materials resistant to the negative effects of an aggressive environment.

In the absence of such a protective coating, it is important to cover all the internal parts of the cabinet with oil paint in 2-3 layers, make on the shelves the sides, the height of which should be 3 cm.

In order to protect the shelves from water ingress, several layers of polyethylene film are laid on them. The placement of furniture in laboratory chemistry is carried out with strict observance of the rules of fire safety.

On the laboratory wall or on the door of the chemistry cabinet, there must necessarily be instructions on labor protection, approved and signed by the director of the educational institution, having the seal of the organization.