In: Chemistry
0.916 g He, 11.780 g F2, and 17.960 g Ar are placed
in a 16.4-L container at 23 oC. What are the molar
concentrations and partial pressures of the gases?
(All values to the nearest 0.0001)
gas | Molar concentration | Partial pressure |
---|---|---|
He | M | atm |
F2 | M | atm |
Ar | M | atm |
What is the total pressure in the container?
P = atm
Molar mass of helium = 4 g/mol
Moles of helium = 0.916/4 = 0.229 mol
Molar concentration of helium = moles of He/ volume of the container
= 0.229/16.4
= 0.014 M
From ideal gas law,
PV= nRT
Where,
P = pressure
V= volume = 16.4 L
n = number of moles = 0.229 mol
R = gas constant = 0.082 L atm mol-1K-1
T = temperature = 23 oC = (273 + 23) = 296 K
or, n/V = P/RT
or, 0.229/16.4 = P/ 0.082 x 296
or, P = 0.34 atm
Therefore the partial pressure of helium = 0.34 atm
--------------------------------------------
Molar mass of fluorine = 38 g/mol
Moles of fluorine= 11.780/38 = 0.310 mol
Molar concentration of fluorine= moles of F2/ volume of the container
= 0.310/16.4
= 0.019 M
From ideal gas law,
PV= nRT
Where,
P = pressure
V= volume = 16.4 L
n = number of moles = 0.310 mol
R = gas constant = 0.082 L atm mol-1K-1
T = temperature = 23 oC = (273 + 23) = 296 K
or, n/V = P/RT
or, 0.310/16.4 = P/ 0.082 x 296
or, P = 0.46 atm
Therefore the partial pressure of fluorine = 0.46 atm
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Molar mass of argon = 40 g/mol
Moles of argon= 17.96/40 = 0.449 mol
Molar concentration of argon = mole of Ar/ volume of the container
= 0.449/16.4
= 0.027 M
From ideal gas law,
PV= nRT
Where,
P = pressure
V= volume = 16.4 L
n = number of moles = 0.449 mol
R = gas constant = 0.082 L atm mol-1K-1
T = temperature = 23 oC = (273 + 23) = 296 K
or, n/V = P/RT
or, 0.449/16.4 = P/ 0.082 x 296
or, P = 0.66 atm
Therefore the partial pressure of argon = 0.66 atm
---------------
Total pressure in the container = (0.34 + 0.46 + 0.66) = 1.46 atm