Introduction
Stoichiometry refers to the molar relationship of elements within a chemical entity, such as a multielemental ion, mole-cule, or mineral. The definition of stoichiometry can be illustrated with an example based on albite feldspar, a common rock-forming silicate mineral. Albite has the following chemical formula: NaAlSi3O8. The stoichiometry of this formula indicates that 1 mole of albite contains 1 mole of sodium (Na) atoms, 1 mole of aluminum (Al) atoms, 3 moles of silicon (Si) atoms, and 8 moles of oxygen (O) atoms. As a reminder, a mole is defined in terms of Avogadro's number: 6.023 × 10+23 mol−1.
Stoichiometry can also be used in reference to the molar relationship between reactants and products for any type of chemical reaction. As an example, the reaction of quartz with water can be represented by the following dissolution (forward) or precipitation (backward) reaction:
The reaction in the forward direction can be interpreted in terms of 1 mole of quartz...
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Cross-references
Acids and bases; Aqueous solutions; Atomic mass unit, Avogadro constant and mole; Chemical kinetics; Clay minerals–ion exchange; Crystal chemistry; Experimental mineralogy and petrology; Geochemical thermodynamics; Hydrothermal solutions; Mineral defects; Mineral genesis; Mineralogy; Phase equilibria; Solid solution; Solubility
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Hellmann, R. (1998). Stoichiometry . In: Geochemistry. Encyclopedia of Earth Science. Springer, Dordrecht. https://doi.org/10.1007/1-4020-4496-8_298
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DOI: https://doi.org/10.1007/1-4020-4496-8_298
Publisher Name: Springer, Dordrecht
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