Hydrobromic acid (another name for hydrogen bromide) is an inorganic compound of hydrogen (H) with bromine (Br). It is a colorless gas that forms a thick fog in humid air.
What are the methods for producing hydrogen bromide
Due to the high degree of oxidation of hydrobromic acid, it cannot be obtained by exposure to sulfuric acid concentrated on alkali metal bromides. The following reaction occurs:
2KBr (potassium bromide) + 2H2SO4 (sulfuric acid) = K2SO4 (potassium sulfate) + SO2 (sulfur oxide) + Br2 (bromine molecule) + 2H2O (water)
1. In industry, the production of acids, such as hydrobromic, is carried out by means of a reaction during which the constituent elements interact. For example, the substance we are considering can be obtained in the following way:
H2 (hydrogen molecule) + Br2 (bromine molecule) = 2HBr (hydrobromic acid)
This reaction is feasible at temperatures from 200 to 400 degrees.
2. It is also possible to obtain hydrobromic acid in the laboratory in several ways.
- by hydrolysis of phosphorus pentabromide or tribromide:
PBr3 (tribromide) + 3H2O (three water molecules) = H3PO3 (phosphoric acid) + 3HBr (hydrobromic acid, chemical formula)
PBr5 (pentabromide) + 4H2O (four water molecules) = H3PO4 (phosphoric acid) + 5HBr (hydrogen bromide)
- by reducing bromine:
3Br2 (three bromine molecules) + S (sulfur) + 4H2O (water) = (reaction is possible at a temperature of 100-150 degrees) H2SO4 (sulfuric acid) + 6HBr (hydrogen bromide)
3Br2 (three bromine molecules) + KNO2 (potassium nitrite) + 4H2O (water) = KNO3 (potassium nitrate) + 2HBr (hydrogen bromide)
- by displacing alkali metals with dilute acid from bromides:
KBr (potassium bromide) + H2SO4 (sulfuric acid) = KHSO4 (potassium hydrosulfate) + HBr (liberated as a gas)
3. As a by-product of hydrogen bromide can be obtained in the synthesis of organic bromine derivatives.
Physical properties of hydrogen bromide:
1. Hydrobromic acid is a colorless gas with an unpleasant and pungent odor. He smokes heavily in the air. It has high temperature resistance.
2. It is well soluble in H2O (water) and ethanol with the formation of an electrolyte. An aqueous solution of hydrogen bromide forms an azeotropic mixture that boils at a temperature of 124 degrees. About one liter of hydrogen bromide dissolves in one liter of water (at 0 degrees).
3. In the process of cooling an aqueous solution of hydrogen bromide, the following crystalline hydrates can be obtained: HBr * H2O, HBr * 2H2O, HBr * 4H2O.
4. Pure hydrogen bromide forms syngony crystals of the orthorhombic, space group F mmm.
5. At a temperature of -66.8 degrees it goes into a liquid state, and at - 87 degrees it hardens.
Chemical properties of hydrogen bromide:
1. Hydrobromic acid, when reacted with water, forms a strong monobasic acid. This reaction looks like this:
HBr + H2O (water) = Br- (bromine anion) + H3O + (hydroxonium ion)
2. This substance is resistant to high temperatures, however, at 1000 degrees, about 0.5% of all molecules decompose:
2HBr (hydrobromic acid) = H2 (hydrogen molecule) + Br2 (bromine molecule)
3. The chemical compound under consideration reacts with various metals, as well as their bases and oxides. Reaction examples:
2HBr + Mg (magnesium) = MgBr2 (magnesium bromide) + H2 (liberated as a gas)
2HBr + CaO (calcium oxide) = CaBr2 (calcium bromide) + H2O (water)
HBr + NaOH (sodium hydroxide) = NaBr (sodium bromide) + H2O (water)
4. Hydrogen bromide is also a reducing agent. It slowly oxidizes in air. For this reason, its aqueous solutions after some time turn brown. The reaction will be like this:
4HBr (hydrobromic acid) + O2 (oxygen molecule) = 2Br2 (bromine molecule) + 2H2O (water)
Application
Hydrogen bromide is used to create (synthesize) various organic derivatives of bromine and to prepare bromides of various metals. Of particular importance is silver bromide, as it is used in the production of film materials.
How is transportation
In cylinders with a capacity of 68 or 6.8 liters under pressure in 24 atmospheres.