Inorganic chemistry

Inorganic chemistry is a subdiscipline of chemistry involving the scientific study of the properties and reactions of all chemical elements and chemical compounds other than the vast number of organic compounds (compounds containing at least one carbon-hydrogen chemical bond).

There are a number of subdivisions of inorganic chemistry such as the four subdivisions of the American Chemical Society's Division of Inorganic Chemistry, namely organometallic chemistry, bioinorganic chemistry, solid-state chemistry and nanoscience.

Inorganic chemistry is closely related to other disciplines such as materials science, earth science, mineralogy, geology and crystallography.

Distinctions between inorganic and organic chemistry

The distinction or boundary between inorganic chemistry and organic chemistry is not very well defined. In general, the above definition of inorganic chemistry seemingly excludes carbon compounds but it does not exclude elemental carbon itself. Hence, carbon oxides, carbon sulfides, metallic carbides and carbonates are included as inorganic compounds.

As another example of the ill-defined distinction between inorganic and organic chemistry, oxalic acid (H₂C₂0₄) is commonly considered to be an organic compound even though it does not contain a carbon-hydrogen bond.

Analysis and characterization of inorganic compounds

The number of known chemical elements that occur naturally on Earth is 94 and the number of diverse inorganic chemical compounds derived by combinations of those elements is virtually innumerable. The characterization of those compounds includes the measurement of chemical and physical properties such as boiling points, melting points, density, solubility, refractive index and the pH and electrical conductivity of solutions.

The techniques of qualitative and quantitative analytical chemistry can provide the composition of a chemical compound in terms of its constituent chemical elements and can thus determine the chemical formula of a compound.

Modern laboratory equipment and techniques can provide many more details for characterizing chemical compounds. Some of the more commonly used modern techniques are:

• Chromatography: A process for separating mixtures into their component constituents.
• X-ray diffraction or X-ray crystallography: A technique that determines three-dimensional arrangement of atoms within a molecule.
• Spectrometry or qualitative Spectroscopy: A technique for the identification of substances through the electromagnetic spectrum emitted from or absorbed by them.
• Voltammetry: An electrochemical method for studying a chemical substance by measuring the electrical potential and/or electric current in an electrochemical cell containing the substance.