4.00 g of He, 20.0 g F2, and 12.0 g Ar are placed in a 12.0-L container at 18.0 °C.
The partial pressure of F2 is _____ atm.
Answers
Explanation:
We use Dalton's Law of Partial Pressures, the which states that in a gaseous mixture, the pressure exerted by a component gas is the same as that it would exert if it ALONE occupied the container... The total pressure is the sum of the individual partial pressures.
Now
P
=
n
R
T
V
, and we solve for the partial pressures individually....
1
⋅
m
o
l
×
0.0821
⋅
L
⋅
a
t
m
⋅
K
−
1
⋅
m
o
l
−
1
×
291.15
⋅
K
12.0
⋅
L
partial pressure of dihydrogen
P
H
2
=
1.99
⋅
a
t
m
20
⋅
g
38.0
⋅
g
⋅
m
o
l
−
1
×
0.0821
⋅
L
⋅
a
t
m
⋅
K
−
1
⋅
m
o
l
−
1
×
291.15
⋅
K
12.0
⋅
L
partial pressure of difluorine
P
F
2
=
1.05
⋅
a
t
m
12
⋅
g
39.95
⋅
g
⋅
m
o
l
−
1
×
0.0821
⋅
L
⋅
a
t
m
⋅
K
−
1
⋅
m
o
l
−
1
×
291.15
⋅
K
12.0
⋅
L
partial pressure of argon
P
A
r
=
0.598
⋅
a
t
m
And
P
Total
=
P
H
2
+
P
F
2
+
P
A
r
=
?
?
⋅
a
t
m