fugacity,
,
Of a substance
B
,
or
, in a gaseous mixture is defined by
, where
is the
partial pressure
of B and
its
absolute activity
.
Source:
Green Book, p. 50
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.)
, 
or
,
in a gaseous mixture is defined by
,
where
is the partial pressure of B and
its absolute activity.