Chemical potential: Difference between revisions
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== The proton chemical potential == | |||
:::: The standard chemical potential of protons is by defintion zero. Therefore, ''ยต''<sub>H</sub><small>+</small> depends on the activity of protons only, | |||
''ยต''<sub>H</sub><small>+</small> = ''RT ln(''a''<sub>H</sub><small>+</small>) | |||
Since pH = -lg(''a''<sub>H</sub><small>+</small>), ''ยต''<sub>H</sub><small>+</small> is related to pH as, | |||
''ยต''<sub>H</sub><small>+</small> = -''RT''ยทln(10)ยทpH | |||
Therefore, for a difference of pH of -1 unit, ฮ''ยต''<sub>H</sub><small>+</small> equals -''RT''ยทln(10): | |||
[[File:Table RT.png|left|400px|thumb|]] | |||
0 ยฐC = 273.15 K | |||
ln(10) = 2.302585093 |
Revision as of 12:31, 18 October 2018
Description
The chemical potential of a substance B, ยตB [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,
ยตB = (โG/โnB)T,p,njโ 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,
ยตB = ยตBยฐ + RT ln(aB)
The standard state for the solute is refered to ideal behaviour at standard concentration, cยฐ = 1 mol/L, exhibiting infinitely diluted solution behaviour.
Abbreviation: ยต
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, ยตH+ depends on the activity of protons only,
ยตH+ = RT ln(aH+)
Since pH = -lg(aH+), ยตH+ is related to pH as,
ยตH+ = -RTยทln(10)ยทpH
Therefore, for a difference of pH of -1 unit, ฮยตH+ equals -RTยทln(10):
0 ยฐC = 273.15 K
ln(10) = 2.302585093