Chemical decomposition

Chemical decomposition or analysis is the separation of a chemical compound into elements or smaller compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis.

A broader definition of the term decomposition also includes the breakdown of one phase into two or more phases.

There are broadly 3 types of decomposition reactions: thermal, electrolytic and catalytic.

Reaction formula

The generalized reaction formula for chemical decomposition is:

AB → A + B

with a specific example being the electrolysis of water to gaseous hydrogen and oxygen:

2H₂O → 2H₂ + O₂

Additional examples

An example of spontaneous decomposition is that of hydrogen peroxide, which will slowly decompose into water and oxygen:

2H₂O₂ → 2H₂O + O₂

Carbonates will decompose when heated, a notable exception being that of carbonic acid, H₂CO₃. Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages, will decompose over time (spontaneously) into carbon dioxide and water

H₂CO₃ → H₂O + CO₂

Other carbonates will decompose when heated producing the corresponding metal oxide and carbon dioxide. In the following equation M represents a metal:

MCO₃ → MO + CO₂

A specific example of this involving calcium carbonate:

CaCO₃ → CaO + CO₂

Metal chlorates also decompose when heated. A metal chloride and oxygen gas are the products. sting procedure in which changes in weight of a specimen are recorded as the specimen is heated in air or in a controlled atmosphere such as nitrogen. Sponsored Links Composites Manufacturing Machines for fiber/tape placement, filament winding, prepreg making. www.mikrosam.com Get Chlor-Alkali Prices From THE most trusted source of C-A data in global markets--Harriman. www.Harriman.co.uk Properties plastics Mechanical properties of polymers with our Polymers datasheets www.Omnexus.com Thermogravimetric curves (thermograms) provide information regarding polymerization reactions, the efficiencies of stabilizers and activators, the thermal stability of final materials, and direct analysis.

MClO₃ → MCl + O₂

A common decomposition of a chlorate to evolve oxygen utilizes potassium chlorate as follows:

2KClO₃ → 2KCl + 3O₂

See also

• Analytical chemistry
• Thermal decomposition

External links

• Biodegradation database