Chemical potential: Difference between revisions

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, µ_B [J/mol], is the partial derivative of Gibbs energy, G [J], per amount of B, n_B [mol], at constant temperature, pressure, and composition other than that of B,

µ_B = (∂G/∂n_B)_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,

µ_B = µ_B° + RT ln(a_B)

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, µ_H+ depends on the activity of protons only,

µ_H+ = RT ln(a_H+)

Since pH = -lg(a_H+), µ_H+ is related to pH as,

µ_H+ = -RT·ln(10)·pH

Therefore, for a difference of pH of -1 unit, Δµ_H+ equals -RT·ln(10):

0 °C = 273.15 K

ln(10) = 2.302585093

@@ Line 12: / Line 12: @@
 |mitopedia concept=Ergodynamics
 }}
+== 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|]]
+°C = 273.15 K
+ln(10) = 2.302585093