Please show me how to do this problem; What is the mole fraction of N 2 in a gas

Question

Please show me how to do this problem;

What is the mole fraction of N2 in a gas mixture containing 22.3 g of O2, 15.9 g of NH3, and whose volume at STP is 80.0L?

Select one:

a. 0.456

b. 0.544

c. 0.928

d. 0.995

and this one, I am not getting any of the answers when I use P1/T1=P2/T2, not sure what I'm doing wrong...

A basketball is inflated to a pressure of 1.90 atm in a 24.0°C garage. What is the pressure of the basketball outside where the temperature is -1.00°C?

Select one:

a. 1.74 atm

b. 1.80 atm

c. 2.00 atm

d. 2.08 atm

Explanation / Answer

80 L correspond to 80/22.4= 3.57 moles

Total moles of mixture=3.57

Moles of Oxygen= mass/ molecular weight = 22.3/32= 0.6969

Moles of Ammonia = mass/ molecular weight= 15.9/17= 0.9353

Moles of nitrogen= Total moles of mixture- ( Moles of oxygen+ moles of ammonia) =3.57-(0.6968+0.9352)=1.9378

Mole fraction of N2= moles of nitrogen/ total moles = 1.9378/3.67=0.542

(b is the correct answer)

V1 remains the same

P1/T1= P2/T2

P1= 1.9 atm and T1= 24+273.15= 297.15 K

P2= ? T2= -1+273.15= 272.15K

1.9/ (297.15)= P2/(272.15)

P2= 1.9*272.15/ 297.15 =1.74 atm ( a is the correct answer)

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.