Answer:
5 moles of Argon is present in the mixture.
Explanation:
Total pressure of the gaseous mixture = 4 atm
Total number of moles = 16
Partial pressure of Ne = 2.75 atm
By Dalton's law of partial pressure, the total pressure of gaseous mixture is the sum of partial pressures of individual gases which are non-reactive.
Hence:
[tex]P_{total}=P_{Ar}+P_{Ne}\\4=P_{Ar}+2.75\\P_{Ar}=1.25\ atm[/tex]
Also :
Partial pressure = mole fraction*total pressure
[tex]P_{Ar}=X_{Ar}P_{total}[/tex]
[tex]X_{Ar}=\frac{1.25}{4}=0.3125[/tex]
[tex]\frac{n_{Ar}}{n_{total}}=0.3125\\n_{Ar}=5[/tex]
∴Number of moles of Argon = 5