## transfer activity coefficient, $$\mathit{\gamma}_{\text{t}}$$

https://doi.org/10.1351/goldbook.T06442
A term used to quantify the difference in the @[email protected] of a solute ion in two different standard states often in two different liquid phases. The relationship is $$\Delta _{\text{t}}G^{\,\unicode{x26ac}} = \nu \ R\ T\ \ln \mathit{\gamma}_{\text{t}}$$ where $$\Delta _{\text{t}}G^{\,\unicode{x26ac}}$$ is the transfer Gibbs energy and $$\nu$$ is the number of ions in the solute.
Notes:
1. It should not be confused with the mass transfer @[email protected] which represents the specific rate of transfer of a species from one phase to another.
2. It does not necessarily imply the physical transfer of a solute between two liquid phases.