Chlorine trifluoride is a compound that is characterized by extremely strong chemical activity. Under its influence, almost all substances are oxidized, including glass. Chlorine trifluoride is toxic and has a destructive effect on living organisms. One of the interesting facts associated with this connection is that in Nazi Germany they planned to use it as a weapon. In the USA in 1943, attempts were also made to use it as fuel for high-speed submarines, but they failed.
Description
Chlorine trifluoride, the formula of which is ClF 3 , is a colorless gas with a strong odor. When it gets on organic and inorganic substances, in many cases they self-ignite (even those that are fire resistant, such as asbestos), since it is a powerful oxidizing agent. In this regard, for a long time it was difficult to obtain ClF 3 and its storage.
Gas can be condensed and kept for a long time in special cylinders. Condensation occurs at a temperature of 285 ° K or with increasing pressure. In this state, this substance looks like a greenish-colored liquid. The article provides a photo of chlorine trifluoride, reflecting its structure. A study of the infrared absorption spectrum led to the conclusion that this compound has a T-shaped structure of molecules.
Physiochemical properties
The main characteristics of chlorine trifluoride are:
- melting point - 196 ° K;
- boiling point - 284 ° K;
- molecular weight under normal conditions, 92.457 g / mol;
- electrical conductivity at 25 ° C - 3.1 × 10 -9 Ohm -1 ∙ cm -1 ;
- fluorine content - 61%;
- the density at 25 ° C is 1.8 g / cm 3 .
This substance is the most reactive of all halogen fluorides and a strong oxidizing agent. It can react violently even with water. With some compounds, the reaction proceeds with an explosion.
ClF 3 in the gaseous state when it is irradiated with positively charged alpha particles decomposes. Decomposition products are chlorofluoride monofluoride and fluorine.
The reaction with organic substances occurs with self-ignition, so their fluorination is practically uncontrollable.
Getting
This compound was first synthesized in 1930. Purified fluorine and chlorine were fed into a heated copper reactor. Chlorine mono- and trifluoride was formed in it, which condensed in the first receiver at -70 ° , in the second receiver ClF was captured (at t = -150 ° ), and in the third there was liquid air to freeze excess fluorine. A tube filled with calcined KF was attached to the last receiver, which served as protection against atmospheric moisture.
Since this substance is very chemically active, in its synthesis, equipment made of copper (stable up to 400 ° C), nickel (up to 750 ° C) and their alloys (monel) can be used. This is due to the formation of a protective fluoride film on their surface. In laboratory conditions, utensils made of fluoroplastic or monel metal are used, since this compound is capable of igniting glass.
Application
Chlorine trifluoride is able to interact with all elements except platinum, oxygen and nitrogen. Therefore, this substance is considered, first of all, as a fluorinating agent for the production of various compounds containing fluorine.
A mixture of pentaborane and chlorine trifluoride is of particular interest for use as rocket fuel. During the Second World War, Nazi scientists conducted research, studying the possibility of using this substance as cheap chemical weapons and raw materials for flamethrowers and bombs. They made about 30 tons of chlorine trifluoride, but they were not used. This compound is currently subject to the Chemical Weapons Convention.
Abroad, chlorine trifluoride is also used to increase flame temperature during welding and cutting of metals (as an additive to welding gas). Studies are being conducted on the feasibility of using ClF 3 for the recovery of nuclear fuel.
Due to the difficulty of carrying out experimental work, this substance has not yet been adequately studied, especially with regard to its chemical properties. Fluoride-containing materials are currently widely used as fluxes in steelmaking, welding, soldering, as well as in electronics and laser technology.
Effects on the human body
Chlorine trifluoride is a very toxic compound. In addition to the burns that it causes due to its increased oxidizing ability, ClF 3 has a choking effect and affects the lungs.
In the process of reaction with the environment, chlorine trifluoride forms hydrofluoric acid vapors, which lead to acute and chronic poisoning. Acid belongs to the 2nd hazard class, as well as the original substance. The maximum MAC of chlorine trifluoride in the air is 0.4 mg / m 3 . Attempts to neutralize the flame with water cause an explosive reaction.