In nature, a great many different acids. Some of them are organic, others are inorganic. Hydrofluoric acid belongs to the inorganic class. She has several more names - hydrofluoric, hydrofluoric, hydrofluoride. What is this substance? What are the properties of hydrofluoric acid?
Hydrofluoric Acid: Physical and Chemical Properties
Hydrofluoric acid is a liquid substance, easily mobile, has a rather pungent odor, has a pungent taste (reminiscent of concentrated acetic acid). Hydrofluoric acid is weak (the strength of acids is determined by the dissociation constant, for a given substance this value is 6.8 * 10 -4 ). Due to the fact that this acid intensively interacts with glass (more precisely, with silicon oxide), storage is provided in plastic bottles (containers).
Hydrofluoric acid is characterized by reactions with metals, resulting in the formation of salts of these metals, called fluorides.
Storage Conditions and Precautions
Hydrofluoric acid can be stored not only in a plastic container, but also in dishes made of paraffin, chlorovinyl, platinum and fluoroplastic. Storage in organic glass vessels is also possible. Large volumes of acid are stored in steel sealed tanks. Work with this substance is mandatory when the exhaust system is turned on, and the draft should be very, very good. The use of rubber gloves is also required. In case of acid fire, quenching is possible with water. If there is vapor in the air (gaseous hydrogen fluoride), it is imperative to use a gas mask.
Areas of use
Hydrofluoric acid is used as a catalyst for processes (hydrogenation, dehydrogenation, alkylation), for the dissolution of certain metals and the destruction of rocks (silicate). Also used when welding with electrodes or submerged arc welding (the lubricant contains fluorine compounds, including hydrofluoric acid). Hydrofluoric acid is used in the production of fluorosulfonic acid and for the production of fluorine.
Toxic Properties of Hydrofluoride Acid
The acid in question is a very toxic substance. It has a narcotic effect, albeit weak. It has an irritating effect on the skin, respiratory system, mucous membranes. A particular danger of hydrofluoric acid is the delay in the action it has, that is, when an acid gets on the skin, a person does not feel any sensations, it penetrates the skin, and then not only causes a chemical burn, but also swelling, pain, and poisoning. Symptoms may begin one day after interaction with hydrofluoric acid. The hazard class is assigned to it second, that is, it belongs to the class of highly hazardous substances.
To prevent any kind of dangerous consequences of working with hydrofluoride acid, it is necessary to strictly observe the rules for its operation.
Acid hazard classes: some examples
Acids can be called perhaps the most dangerous class of chemicals. They not only have a clear negative effect (burns, irritations), but they are also poisonous, toxic substances. There is a certain division of substances into hazard classes:
- 1st class of danger - substances are extremely dangerous. Some acids belong to this class, among them terephthalic.
- 2nd hazard class - high hazard substances. Not only hydrofluoric acid belongs to this class, but also sulfuric acid.
- 3rd hazard class - moderately hazardous substances. Nitric acid can serve as an example of substances of this class, as well as hydrochloric and some others.
- 4th hazard class - low hazard substances. Carbon dioxide belongs to this class.
That is why there are strict rules for working with a particular substance that do not need to be violated. Provided that your health is dear to you.