Chlorine is capable of forming several different oxides.
All of them are used in industry in large volumes, since they are in demand in many areas of industry.
Chlorine forms a number of oxides with oxygen, the total number of which is five. All of them can be described by the general formula ClxOy. In them, the valence of chlorine varies from 1 to 7.
Valence of different chlorine oxides is different: Cl2O - 1, Cl2O3 - 3, ClO2 - 4, Cl2O6 - 6, Cl2O7 - 7.
Chlorine oxide (I) is used for the production of hypochlorites, which are strong bleaching and disinfecting agents.
Chlorine oxide (II) is actively used for bleaching flour, cellulose, paper and other things, as well as for sterilization and disinfection.
Chlorine oxide (VI) and chlorine oxide (VII) are used for the synthesis of organic compounds.
Preparation of Cl2O
This oxide in large-capacity production is obtained in two ways.
1. By the method of Peluz. A reaction is carried out between gaseous chlorine and mercury oxide. Depending on the conditions, another mercury compound may form, but the target product remains. After that, the gaseous chlorine oxide is liquefied at a temperature of -60 degrees Celsius.
The reaction equations describing the Peluse method:
2HgO + Cl2 = Hg2OCl2 + Cl2O
HgO + 2Cl2 = HgCl2 + Cl2O
2. The interaction of chlorine with an aqueous solution of sodium carbonate by reaction:
2Cl2 + 2Na2CO3 + H2O = 2NaHCO3 + Cl2O + 2NaCl
Sodium carbonate can be replaced with other alkali or alkaline-earth metal carbonates.
Preparation of ClO2
The only industrial method for the production of chlorine dioxide is based on the interaction of sodium chlorate and sulfur dioxide in an acidic medium. The result of this interaction is the reaction:
2NaClO3 + SO2 + H2SO4 = 2NaHSO4 + ClO2
Preparation of Cl2O6
In industry, Cl2O6 is produced by the interaction of chlorine dioxide with ozone:
2ClO2 + 2O3 = 2O2 + Cl2O6
Preparation of Cl2O7
1. Careful heating of perchloric acid with phosphoric anhydride leads to the separation of an oily liquid, which is chlorine (VII) oxide. The whole process is described by the reaction:
2HClO4 + P4O10 = H2P4O11 + Cl2O7
2. The second way of obtaining this oxide is connected with electricity. If electrolysis of perchloric acid solution is carried out, Cl2O7 can be found in the anode space.
3. Heating in vacuum of perchlorates of transition metals leads to the formation of chlorine oxide (VII). The most often heated niobium perchlorate or molybdenum.
Physical properties of oxides
Cl2O: under standard conditions, a brownish-yellow gas with a chlorine smell, and at a temperature below +2 degrees Celsius, a golden-red liquid. Explosive in high concentrations.
ClO2: Under standard conditions - gas with a characteristic smell of red-yellow color, at a temperature below +10 degrees Celsius - a red-brown liquid. Explodes into light, in the presence of reducing agents and with heating.
Cl2O6: An unstable gas that begins to decompose at a temperature of 0 to +10 degrees Celsius with the formation of chlorine dioxide, at 20 degrees Celsius chlorine is formed. Due to the formation of chlorine dioxide - explosive.
Cl2O7: colorless oily liquid, which when heated above 120 degrees Celsius explodes. Can detonate from impact.