Difference between revisions of "Molar mass"

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high-resolution terminology - matching measurements at high-resolution

Molar mass

Description

Molar mass M is the mass of a chemical compound divided by its amount-of-substance measured in moles. It is defined as M_B = m/n_B, where m is the total mass of a sample of pure substance and n_B is the amount of substance B given in moles. The definition applies to pure substance. The molar mass allows for converting between the mass of a substance and its amount for bulk quantities. It is calculated as the sum of standard atomic weights of all atoms that form one entity of the substance.

The appropriate SI base units is kg·mol^-1. However, for historical as well as usability reasons, g·mol^-1 is almost always used instead.

Abbreviation: M [kg·mol^-1]; [g·mol^-1]

Related terms

The relative molecular mass is represented by the symbol M_r and defined as M_R = m_f/m_u. It is the mass of an entity (this can be a molecule or a formula unit: a group of atoms by the way the chemical formula is written) divided by the unified atomic mass unit. Since mass is divided by mass, the relative molecular mass is dimensionless.

The relative molar mass and the molecular weight are alternative terms for the relative molecular mass according to IUPAC's Green Book or Gold Book. Despite this definition, the term "molecular weight" is widely used as a synonym for the molar mass.

The formula weight is another synonym of the molar mass that is not covered by the IUPAC definition. For historical reasons and for non-molecular compounds, such as ionic salts, it is still frequently used.

References

Bioblast link	Reference	Year
Bureau International des Poids et Mesures 2019 The International System of Units (SI)	Bureau International des Poids et Mesures (2019) The International System of Units (SI). 9th edition:117-216. ISBN 978-92-822-2272-0	2019
Cohen 2008 IUPAC Green Book	Cohen ER, Cvitas T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor HL (2008) Quantities, Units and Symbols in Physical Chemistry. IUPAC Green Book 3rd Edition, 2nd Printing, IUPAC & RSC Publishing, Cambridge.	2008
BEC 2020.1 doi10.26124bec2020-0001.v1	Gnaiger E et al ― MitoEAGLE Task Group (2020) Mitochondrial physiology. Bioenerg Commun 2020.1. https://doi.org/10.26124/bec:2020-0001.v1	2020

Keywords

Bioblast links: Concentration and pressure - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>

Concentration

» Volume

» Activity

» Concentration

» Density

» Mole

» Molar mass

Pressure

» Barometric pressure

» Chemiosmotic pressure

» Gas pressure

» Osmotic pressure

» Oxygen pressure

» pascal

» Pressure

Solubility = concentration/pressure

» Solubility

» Solubility factor

» Oxygen solubility

General

» Boltzmann constant

» Energy

» Force

» Gas constant

» Work

Related keyword lists

» Keywords: Oxygen signal

» Keywords: Normalization

MitoPedia concepts: MiP concept

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-{{MitoPedia}}
+{{MitoPedia
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+|abbr=''M'' [kg·mol<sup>-1</sup>]; [g·mol<sup>-1</sup>]
-{{MitoPedia methods}}
+|description='''Molar mass''' ''M'' is the mass of a <!--component--> chemical compound divided by its amount-of-substance measured in moles. It is defined as ''M''<sub>B</sub> = ''m''/''n''<sub>B</sub>, where ''m'' is the total mass of a sample of pure substance and ''n''<sub>B</sub> is the amount of substance B given in moles. The definition applies to pure substance. The molar mass allows for converting between the mass of a substance and its amount for bulk quantities. It is calculated as the sum of standard atomic weights of all atoms that form one entity of the substance.
-{{MitoPedia O2k and high-resolution respirometry}}
-{{MitoPedia topics}}
+The appropriate [[SI base units]] is kg·mol<sup>-1</sup>. However, for historical as well as usability reasons, g·mol<sup>-1</sup> is almost always used instead.
+<!--
+is a derived quantity based on the SI base quantity [[length]] [m] and is expressed in terms of [[SI base units]] in the derived unit cubic meter [m<sup>3</sup>]. The liter [L = dm<sup>3</sup>] is a conventional unit of volume for concentration and is used for most solution chemical kinetics. The volume ''V'' contained in a system (experimental chamber) is separated from the environment by the system boundaries; this is called the volume of the system, and described in practical language as big/small (derived from [[length]], [[height]]) or voluminous. Systems are defined at constant volume or constant [[pressure]]. For a pure sample S, the volume ''V''<sub>S</sub> of the pure sample equals the volume ''V'' of the system, ''V''<sub>S</sub> = ''V''. For [[sample]] s in a mixture, the ratio ''V''<sub>s</sub>·''V''<sup>-1</sup> is the nondimensional [[volume fraction]] ''Φ''<sub>s</sub> of sample s. Quantities divided by volume are [[concentration]]s of sample s in a mixture, such as [[count]] concentration ''C<sub>X</sub>'' = ''N<sub>X</sub>''·''V''<sup>-1</sup> [x·L<sup>-1</sup>], and amount of substance concentration ''C''<sub>B</sub> = ''n''<sub>B</sub>·''V''<sup>-1</sup> [mol·L<sup>-1</sup>]. Mass concentration is [[density]] ''ρ''<sub>s</sub> = ''m''<sub>s</sub>·''V''<sup>-1</sup> [kg·L<sup>-1</sup>]. In closed compressible systems (with a gas phase), the concentration of the gas increases, when pressure-volume [[work]] is performed on the system.-->
+|info=<!--[[BEC 2020.1]], [[Gnaiger MitoFit Preprints 2020.4]]-->
+}}
+== Related terms ==
+The '''relative molecular mass''' is represented by the symbol ''M''<sub>r</sub> and defined as ''M''<sub>R</sub> = ''m''<sub>f</sub>/''m''<sub>u</sub>.  It is the mass of an entity (this can be a molecule or a formula unit: a group of atoms by the way the chemical formula is written) divided by the unified atomic mass unit. Since mass is divided by mass, the relative molecular mass is dimensionless.
+The '''relative molar mass''' and the '''molecular weight''' are alternative terms for the relative molecular mass according to IUPAC's Green Book or [https://goldbook.iupac.org/terms/view/R05271 Gold Book]. Despite this definition, the term "molecular weight" is widely used as a synonym for the molar mass.
+The '''formula weight''' is another synonym of the molar mass that is not covered by the IUPAC definition. For historical reasons and for non-molecular compounds, such as ionic salts, it is still frequently used.
+== References ==
+{{#ask:[[Additional label::Molar mass]]
+| mainlabel=Bioblast link
+|?Has title=Reference
+|?Was published in year=Year
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+}}
+== Keywords ==
+{{Template:Keywords: Concentration and pressure}}
+{{MitoPedia concepts
+|mitopedia concept=MiP concept,
+}}