Page 138 - Gas Adsorption Equilibria

124 Chapter 3

By combining the four measurements, i. e. eqs. (3.1 – 3.4) we can calculate
the reduced mass of the adsorbate defined as the difference between the
mass adsorbed and the buoyancy related to the volume of the sorbent /
sorbate system in the sorptive gas of density i. e. the quantity

According to eqs. (3.1 – 3.4) is given by

which is abbreviated by the symbol the letter “G” indicating the
gravimetric measurement method. This quantity can numerically be calculated
from the results of the four measurements mentioned above, i. e. numerical
values of the moments and some additional balance
parameters It is interesting to note the special form of eq.
(3.6) in case there is no sorbent sample but only a ballast or tare at
the balance Then according to (3.5), and (3.6) delivers the
relation

Here the new moments refer to

a) measurement without a sorbent sample in sorptive gas cp.
eq.(3.1),

b) measurement without a sorbent sample in vacuum cp.
(3.1) or (3.3),

Combining eqs. (3.6), (3.7) we get for the reduced mass adsorbed