1. What is the pressure in a 28.9- L cylinder filled with 40.0 g of oxygen gas a

Question

1. What is the pressure in a 28.9-L cylinder filled with 40.0g  of oxygen gas at a temperature of 327K ?

2.A sample of gas has a mass of 38.6mg . Its volume is 220mL  at a temperature of 56?C and a pressure of 858torr . Find the molar mass of the gas.

3.A gas mixture contains 1.20g N2 and 0.81g O2 in a 1.63-L container at 23?C.

                   A.Calculate the mole fraction of N2.

                   B.Calculate the mole fraction of O2.

                   C.Calculate the partial pressure of N2.

                   D.Calculate the partial pressure of O2.

Explanation / Answer

ans 1)

P = nRT/V

mass = 40g

n = moles = 40/32 = 1.25

V = 28.9 L

T = 327 K

P = 1.25*0.0821*327/28.9 = 1.16 atm

ans 2/)

V = 0.22L

T = 56 C = 329 K

P = 858 torr = 1.129 atm

R = 0.0821

N = PV/RT = 1.129*0.22/0.0821*329 = 0.00919 moles

so moles = mass/molar mass

molar mass = 0.0386/0.00919 = 4.2 gm/mol

ans 3)

moles of N2 = 1.2/28 = 0.0429

moles of O2 = 0.81/32 = 0.0253

V = 1.63 L

T = 23C = 296 K

moles fraction of N2 = 0.0429/(0.0429+0.0253) = 0.629

moles fraction of O2 = 0.0253/(0.0429+0.0253) = 0.371

P = nRT/V = (0.0429+0.0253)*296*0.0821/1.63 = 1.017 atm

Partial pressure of N2 = 1.017*0.629 = 0.639 atm

partial pressure of O2 = 1.017*0.371 = 0.377 atm

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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