In chemistry, a formula unit is the smallest unit of a non-molecular substance, such as an ionic compound, covalent network solid, or metal.[1][2] It can also refer to the chemical formula for that unit. Those structures do not consist of discrete molecules, and so for them, the term formula unit is used. In contrast, the terms molecule or molecular formula are applied to molecules.[3] The formula unit is used as an independent entity for stoichiometric calculations.[4][5] Examples of formula units, include ionic compounds such as NaCl and K2O and covalent networks such as SiO2 and C (as diamond or graphite).[6]
In most cases the formula representing a formula unit will also be an empirical formula, such as calcium carbonate (CaCO3) or sodium chloride (NaCl), but it is not always the case. For example, the ionic compounds potassium persulfate (K2S2O8), mercury(I) nitrateHg2(NO3)2, and sodium peroxideNa2O2, have empirical formulas of KSO4, HgNO3, and NaO, respectively, being presented in the simplest whole number ratios.[7]
In mineralogy, as minerals are almost exclusively either ionic or network solids, the formula unit is used. The number of formula units (Z) and the dimensions of the crystallographic axes are used in defining the unit cell.[8]
Referencesedit
^Peter Atkins, Julio de Paula, Ronald Friedman, Physical Chemistry: Quanta, Matter, and Change, 2nd Edition
^"Does the term Formula Unit apply to giant covalent networks composed of one type of atom, like Diamond or Graphene which have formula C?".
formula, unit, chemistry, formula, unit, smallest, unit, molecular, substance, such, ionic, compound, covalent, network, solid, metal, also, refer, chemical, formula, that, unit, those, structures, consist, discrete, molecules, them, term, formula, unit, used,. In chemistry a formula unit is the smallest unit of a non molecular substance such as an ionic compound covalent network solid or metal 1 2 It can also refer to the chemical formula for that unit Those structures do not consist of discrete molecules and so for them the term formula unit is used In contrast the terms molecule or molecular formula are applied to molecules 3 The formula unit is used as an independent entity for stoichiometric calculations 4 5 Examples of formula units include ionic compounds such as NaCl and K2O and covalent networks such as SiO2 and C as diamond or graphite 6 In most cases the formula representing a formula unit will also be an empirical formula such as calcium carbonate CaCO3 or sodium chloride NaCl but it is not always the case For example the ionic compounds potassium persulfate K2S2O8 mercury I nitrate Hg2 NO3 2 and sodium peroxide Na2O2 have empirical formulas of KSO4 HgNO3 and NaO respectively being presented in the simplest whole number ratios 7 In mineralogy as minerals are almost exclusively either ionic or network solids the formula unit is used The number of formula units Z and the dimensions of the crystallographic axes are used in defining the unit cell 8 References edit Peter Atkins Julio de Paula Ronald Friedman Physical Chemistry Quanta Matter and Change 2nd Edition Does the term Formula Unit apply to giant covalent networks composed of one type of atom like Diamond or Graphene which have formula C Chapter 4 Covalent Bonds and Molecular Compounds wou edu Retrieved 2023 10 08 Formula Units vs Empirical Formula CHEMISTRY COMMUNITY lavelle chem ucla edu Retrieved 2023 09 10 2 2 Chemical Formulas Chemistry LibreTexts 2015 01 27 Retrieved 2023 09 10 Steven S Zumdahl Susan A Zumdahl 2000 Chemistry 5 ed Houghton Mifflin pp 470 6 ISBN 0 618 03591 5 Is Formula Unit usually an empirical formula but not always Chemical Forums chemicalforums com Retrieved 2023 10 06 Smyth Joseph R and Tamsin C McCormick 1995 Crystallographic Data for Minerals American Geophysical Union nbsp This chemistry related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Formula unit amp oldid 1221457045, wikipedia, wiki, book, books, library,
