Answer :
Part A : The partial pressure of argon is, 0.795 atm
Part B : The partial pressure of ethane is, 0.505 atm
Explanation :
Part A :
First we have to calculate the moles of argon.
Molar mass of argon = 39.95 g/mole
[tex]\text{Moles of argon}=\frac{\text{Mass of argon}}{\text{Molar mass of argon}}=\frac{1.30g}{39.95g/mol}=0.0325mole[/tex]
Now we have to calculate the partial pressure of argon.
Using ideal gas equation :
PV = nRT
where,
P = Pressure of argon = ?
V = Volume of argon = 1.00 L
n = number of moles of argon = 0.0325 mole
R = Gas constant = [tex]0.0821L.atm/mol.K[/tex]
T = Temperature of argon = [tex]25^oC=273+25=298K[/tex]
Putting values in above equation, we get:
[tex]P_{Ar}=\frac{nRT}{V}[/tex]
[tex]P_{Ar}=\frac{(0.0325mol)\times (0.0821L.atm/mol.K)\times (298K)}{1.00L}=0.795atm[/tex]
The partial pressure of argon is, 0.795 atm
Part B :
Now we have to calculate the partial pressure of ethane.
As we know that,
Total pressure = Partial pressure of argon + Partial pressure of ethane
1.300 atm = 0.795 atm + Partial pressure of ethane
Partial pressure of ethane = 1.300 - 0.795
Partial pressure of ethane = 0.505 atm
The partial pressure of ethane is, 0.505 atm