Difference between revisions of "Concentration"

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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, c_B = [B] = n_B·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, dc_i, in isolated or closed systems at constant pressure is due to internal transformations (advancement per volume) only. In closed compressible systems (with a gas phase), the concentration of the gas changes, when pressure-volume work is performed on the system. In open systems, a change of concentration can additionally be due to external flow across the system boundaries.

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

c_B = n_B·V^-1 [mol·m^-3]

Charge density in electricity is charge per volume,

ρ = Q_B·V^-1 [C·m^-3]

Mass density is the reciprocal of specific volume,

ρ = m_B·V^-1 [kg·m^-3]

Volume density is equivalent to the volume fraction,

Φ_B = V_B·V^-1.

Total concentration

The total concentration of a substance (e.g. ADP) must be distinguished from the concentration of a specific ionic species (e.g. ADP^4-, MgADP^2-, MgHADP^-).
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 for dissolved gases and at very high dilution. The activity of dissolved gases is expressed as the (relative) partial pressure, e.g. p_O₂). The ratio of concentration, e.g. c_O₂ [µM], and partial pressure, e.g. p_O₂ [kPa], is the solubility (see oxygen solubility, S_O₂).

Keywords: Oxygen signal

Bioblast links: Oxygen signal - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>

Specific

O2k-Procedures

» High signal at zero oxygen

» POS calibration - static

» POS calibration - dynamic

MiPNet O2k-Procedures

» POS-calibration

» O2k-Manual: POS-service

» O2k-cleaning

» O2k-Series G and DatLab 6: Calibration

General

» Oxygen, dioxygen, O₂

» Oxygen calibration - DatLab

» Oxygen solubility

» Oxygen solubility factor

» Oxygen pressure

» Concentration

» Activity

» Pressure - Pascal

» Barometric pressure

» High-resolution respirometry

» OroboPOS

» Polarographic oxygen sensor

» MitoFit Quality Control System

» Sensitivity

Other keyword lists

» Keywords: Concentration and pressure

MitoPedia concepts: MiP concept, Ergodynamics

@@ Line 1: / Line 1: @@
 {{MitoPedia
 |abbr=''c'' [mol·m<sup>-3</sup>]; ''C'' [x·m<sup>-3</sup>]
-|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.
+|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 at constant [[pressure]] is due to internal transformations ([[advancement per volume]]) only. In closed compressible systems (with a gas phase), the concentration of the gas changes, when pressure-volume work is performed on the system. In open systems, a change of concentration can additionally be due to [[external flow]] across the system boundaries.
 |info=[http://goldbook.iupac.org/S05746.html IUPAC Gold Book]
 }}
@@ Line 29: / Line 29: @@
 # 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 '''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>).
+# The '''concentration''' of a substance (''c'') differs from the [[activity]] (''a''), except for dissolved gases and 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>).