Of a substance
B,
or
,
in a gaseous mixture is defined by
,
where
is the
partial pressure of B and
its
absolute activity.
Source:
See also:
PAC, 1994, 66, 539
(Standard quantities in chemical thermodynamics.)
PAC, 1984, 56, 571
(Physicochemical quantities and units in clinical chemistry with special emphasis
on activities and activity coefficients.)