Difference between revisions of "Chemical potential"
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== The proton chemical potential == | |||
:::: The standard chemical potential of protons is by defintion zero. Therefore, ''µ''<sub>H</sub><small>+</small> depends on the activity of protons only, | |||
''µ''<sub>H</sub><small>+</small> = ''RT ln(''a''<sub>H</sub><small>+</small>) | |||
Since pH = -lg(''a''<sub>H</sub><small>+</small>), ''µ''<sub>H</sub><small>+</small> is related to pH as, | |||
''µ''<sub>H</sub><small>+</small> = -''RT''·ln(10)·pH | |||
Therefore, for a difference of pH of -1 unit, Δ''µ''<sub>H</sub><small>+</small> equals -''RT''·ln(10): | |||
[[File:Table RT.png|left|400px|thumb|]] | |||
0 °C = 273.15 K | |||
ln(10) = 2.302585093 | |||
Revision as of 12:31, 18 October 2018
- high-resolution terminology - matching measurements at high-resolution
Chemical potential
Description
The chemical potential of a substance B, µB [J/mol], is the partial derivative of Gibbs energy, G [J], per amount of B, nB [mol], at constant temperature, pressure, and composition other than that of B,
µB = (∂G/∂nB)T,p,nj≠B
The chemical potential of a solute in solution is the sum of the standard chemical potential measured under defined standard conditions and a concentration (activity)-dependent term,
µB = µB° + RT ln(aB)
The standard state for the solute is refered to ideal behaviour at standard concentration, c° = 1 mol/L, exhibiting infinitely diluted solution behaviour.
Abbreviation: µ
Reference: Cohen 2008 IUPAC Green Book
Communicated by Gnaiger E 2018-10-18
MitoPedia concepts: Ergodynamics
The proton chemical potential
- The standard chemical potential of protons is by defintion zero. Therefore, µH+ depends on the activity of protons only,
µH+ = RT ln(aH+)
Since pH = -lg(aH+), µH+ is related to pH as,
µH+ = -RT·ln(10)·pH
Therefore, for a difference of pH of -1 unit, ΔµH+ equals -RT·ln(10):
0 °C = 273.15 K
ln(10) = 2.302585093
