Solutions (^215)
Oxygen does not diffuse through the partitions,
and its pressure in tin middle part of the vessel is
PO4 -
V •
According to Dalton's law, the pressure in a part
of a vessel is equal to the sum of the partial pres-
sures of the gases it contains:
Pi= P^112 1.3 X 10° Pa =1.3 GPa,
P2= PH2+ P^02 + pN2 4.5X 10° Pa = 4.5 GPa,
P11 2 + PN2 2.0 x 10° Pa= 2.0 GPa.
2.8*. Let us first determine the velocity of the
descent module. We note that the change in pres-
sure Ap is connected with the change in altitude
Ah through the following relation:
Ap = —pg Ah, (1)
where p is the gas density. The equation of state
for an ideal gas implies that p = (p/it) RT (here
T is the gas temperature at the point where the
change in pressure is considered). Taking into
account that Ah = —v At, where v is the velocity
of the descent, and At is the time of the descent,
we can write expression (1) in the form
Ap !Iv At
-g RT •
(2)
Knowing the ratio Ap/At, i.e. the slope of the
tangent at the final point A of the graph, we can
determine the velocity v from Eq. (2). (It should
be noted that since the left-hand side of (2) con-
stains the ratio Ap/p, the scale on the ordinate
axis is immaterial.) Having determined (Apt At) p-1^
from the graph and substituting p = 44 g/molmot 3R T