A cylinder of volume 25.0L is filled with He gas at a pressure of 5.Oatm and 450K. How many balloons of capacity of 1.0L can be filled using the same He gas at pressure of 1.0atm and temperature of 300K
Answers
Answer:
Explanation:
O2 gas is collected in a pneumatic trough with a volume of 0.155 L until the height of the water inside the trough is equal to the height of the water outside the trough. The atmospheric pressure is 754 torr, and the temperature is 295 K. How many moles of oxygen are present in the trough? (At 295 K, the vapor pressure of water is 19.8 torr.)
The total pressure in the tube can be written using Dalton’s Law of Partial Pressures:
P
t
o
t
a
l
=
P
H
2
O
+
P
O
2
Rearranging this in terms of
P
O
2
, we have:
P
O
2
=
P
t
o
t
a
l
−
P
H
2
O
Because the height of the water inside the tube is equal to the height of the water outside the tube, the total pressure inside the tube must be equal to the atmospheric pressure. With substitution, we have:
P
O
2
=
P
t
o
t
a
l
−
P
H
2
O
=
754
−
19.8
=
734
torr
=
.966
atm
Next, we apply the Ideal Gas Law:
n
=
P
V
R
T
=
(
.966
atm
)
(
.155
L
)
(
.082
L
⋅
atm
⋅
mol
−
1
⋅
K
−
1
)
(
295
K
)
=
.00619
mol O
2