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Difference between revisions of "Concentration"

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{{MitoPedia
{{MitoPedia
|abbr=''c'' [mol·L<sup>-1</sup>]
|abbr=''c'' [mol·m<sup>-3</sup>]; ''C'' [x·m<sup>-3</sup>]  
|description='''Concentration''' or '''density''' is a volume-specific quantity, expressing the number of particles per volume, the amount of substance per volume, or generally matter in a variety of [[format]]s (amount, charge, mass, volume or energy) per volume of the system. In chemistry, amount concentration is [[amount]] per volume, ''c''<sub>B</sub> = [B] = ''n''<sub>B</sub>·''V''<sup>-1</sup> [mol·m<sup>-3</sup>]. The standard concentration, ''c''°, is defined as 1 mol·dm<sup>-3</sup> = 1 mol·L<sup>-1</sup> = 1 M.  
|description='''Concentration''' [mol·m<sup>-3</sup>] or '''density''' is a volume-specific quantity, expressing the number of particles per volume, the amount of substance per volume, or generally matter in a variety of [[format]]s (amount, charge, mass, volume or energy) per volume of the system. In chemistry, amount concentration is [[amount]] per volume, ''c''<sub>B</sub> = [B] = ''n''<sub>B</sub>·''V''<sup>-1</sup> [mol·dm<sup>-3</sup>]=[mol·L<sup>-1</sup>]. The standard concentration, ''c''°, is defined as 1 mol·L<sup>-1</sup> = 1 M. A ''change'' of concentration of an elementary entity, ''i'', d''c''<sub>''i''</sub>, in isolated or closed [[system]]s is due to internal transformations ([[advancement per volume]]) only, but in open systems it is additionally due to [[external flow]] across the system bounderies.
 
|info=[http://goldbook.iupac.org/S05746.html IUPAC Gold Book]
'''Concentration''' {quote}:
}}
Communicated by [[Gnaiger E]] 2018-10-18 (last update 2020-02-16)
== IUPAC definition ==
:::: '''Concentration''' {quote}:
::::1. Group of four quantities characterizing the composition of a mixture with respect to the volume of the mixture (mass, amount, volume and number concentration).
::::2. Short form for amount (of substance) concentration (substance concentration in clinical chemistry).
:::: {end of quote: [http://goldbook.iupac.org/S05746.html IUPAC Gold Book]}


1. Group of four quantities characterizing the composition of a mixture with respect to the volume of the mixture (mass, amount, volume and number concentration).


2. Short form for amount (of substance) concentration (substance concentration in clinical chemistry).
{end of quote: [http://goldbook.iupac.org/S05746.html IUPAC Gold Book]}
A ''change'' of concentration of an elementary entity, ''i'', in a system, d''c''<sub>''i''</sub>, can be due to internal transformations ([[advancement per volume]]) or [[external flow]] across the open system bounderies. 
|info=[http://goldbook.iupac.org/S05746.html IUPAC Gold Book]
}}
Communicated by [[Gnaiger E]] 2018-10-18 (last update 2020-02-13)
== Concentration in different formats ==
== Concentration in different formats ==
:::: Number concentration or number density is the number of particles (entities, objects) per volume,
:::: Number concentration or number density is the number of particles (entities, objects) per volume,
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# The '''total concentration''' of a substance (e.g. ADP) must be distinguished from the concentration of a specific ionic species (e.g. ADP<sup>4-</sup>, MgADP<sup>2-</sup>, MgHADP<sup>-</sup>).  
# The '''total concentration''' of a substance (e.g. ADP) must be distinguished from the concentration of a specific ionic species (e.g. ADP<sup>4-</sup>, MgADP<sup>2-</sup>, MgHADP<sup>-</sup>).  
# The '''total concentration''' of a substance must be distinguished from the free concentration, if unspecific binding occurs to membranes (e.g. [[TPP]]) or if a substance is bound to BSA (e.g. fatty acids).
# The '''total concentration''' of a substance must be distinguished from the free concentration, if unspecific binding occurs to membranes (e.g. [[TPP]]) or if a substance is bound to BSA (e.g. fatty acids).
# The '''concentration''' of a substance (''c'') differs from the [[activity]] (''a''), except at very high dilution. The activity of dissolved gases is expressed as the (relative) partial pressure (e.g. ''p''<sub>O2</sub>). The ratio of concentration (e.g. ''c''<sub>O2</sub> [µM]) and partial pressure (e.g. ''p''<sub>O2</sub> [kPa]) is the solubility (see [[oxygen solubility]]).
# The '''concentration''' of a substance (''c'') differs from the [[activity]] (''a''), except at very high dilution. The activity of dissolved gases is expressed as the (relative) partial pressure, ''e.g.'' ''p''<sub>O<sub>2</sub></sub>). The ratio of concentration, ''e.g.'' ''c''<sub>O<sub>2</sub></sub> [µM], and partial pressure, ''e.g.'' ''p''<sub>O<sub>2</sub></sub> [kPa], is the solubility (see [[oxygen solubility]], ''S''<sub>O<sub>2</sub></sub>).





Revision as of 10:49, 16 February 2020


high-resolution terminology - matching measurements at high-resolution


Concentration

Description

Concentration [mol·m-3] or density is a volume-specific quantity, expressing the number of particles per volume, the amount of substance per volume, or generally matter in a variety of formats (amount, charge, mass, volume or energy) per volume of the system. In chemistry, amount concentration is amount per volume, cB = [B] = nB·V-1 [mol·dm-3]=[mol·L-1]. The standard concentration, c°, is defined as 1 mol·L-1 = 1 M. A change of concentration of an elementary entity, i, dci, in isolated or closed systems is due to internal transformations (advancement per volume) only, but in open systems it is additionally due to external flow across the system bounderies.

Abbreviation: c [mol·m-3]; C [x·m-3]

Reference: IUPAC Gold Book

Communicated by Gnaiger E 2018-10-18 (last update 2020-02-16)

IUPAC definition

Concentration {quote}:
1. Group of four quantities characterizing the composition of a mixture with respect to the volume of the mixture (mass, amount, volume and number concentration).
2. Short form for amount (of substance) concentration (substance concentration in clinical chemistry).
{end of quote: IUPAC Gold Book}


Concentration in different formats

Number concentration or number density is the number of particles (entities, objects) per volume,
C = N·V-1 [x·m-3]
Amount concentration
cB = nB·V-1 [mol·m-3]
Charge density in electricity is charge per volume,
ρ = QB·V-1 [C·m-3]
Mass density is the reciprocal of specific volume,
ρ = mB·V-1 [kg·m-3]
Volume density is equivalent to the volume fraction,
ΦB = VB·V-1.


Total concentration

  1. The total concentration of a substance (e.g. ADP) must be distinguished from the concentration of a specific ionic species (e.g. ADP4-, MgADP2-, MgHADP-).
  2. The total concentration of a substance must be distinguished from the free concentration, if unspecific binding occurs to membranes (e.g. TPP) or if a substance is bound to BSA (e.g. fatty acids).
  3. The concentration of a substance (c) differs from the activity (a), except at very high dilution. The activity of dissolved gases is expressed as the (relative) partial pressure, e.g. pO2). The ratio of concentration, e.g. cO2 [µM], and partial pressure, e.g. pO2 [kPa], is the solubility (see oxygen solubility, SO2).


Keywords: Oxygen signal


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