where (pKa) p = pressure-shifted dissociation constant; (pKa) 0 = dissociation constant; P= pressure (MPa); V 0 = partial molar volume
change of the activated dissociating acid at atmospheric pressure
(m3/mol); R = universal gas constant, 8.30865 × 10−6(MPa m3)/(K
mol); T = absolute temperature (Kelvin); b = 9.2 × 10−4 MPa (constant for all acids).