Multiple Choice 1) Using the principle of corresponding states, Determine the pr

Question

Multiple Choice

1) Using the principle of corresponding states, Determine the pressure and temperature of He that corresponds to 5 atm and 300K of Oxygen(gas)

P = 505 kPa T = 90 K

P = 505 kPa T= 20 K

P= 22.9 kPa, T = 10 K

P = 229 kPa T = 90 K

2)Calculate how many seconds a heating coil must run with a current of 3.2 A at 14.5V if 10% of the total work performed on the coil was transfered as heat to an expansion of an ideal gas with Vf=85L and Vi=20L at an external pressure of 2.5 bar.

a) 0.24 s

b) 3500 s

c) 250 s

d) 750 s

P = 505 kPa T = 90 K

P = 505 kPa T= 20 K

P= 22.9 kPa, T = 10 K

P = 229 kPa T = 90 K

Explanation / Answer

Ans 1

Law of corresponding states

At the same reduced temperature and reduced pressure, the compressibility factor also remains the same for real gases.

reduced temperature

Tr = T/Tc

Reduced pressure

Pr = P/Pc

For Oxygen gas

T = temperature = 300 K

P = pressure = 5 atm

c subscript represents critical point

For oxygen

Tc = 154.58 K

Pc = 50.768 atm

Tr = 300/154.58 = 1.9407

Pr = 5/50.768 = 0.0984

For helium

Tc = 5.1950 K

Pc = 2.2452 bar

At the same reduced properties

T = Tr x Tc

= 1.9407 x 5.1950

= 10.08 K

P = Pr x Pc = 0.0984 x 2.2452

= 0.2209 atm x 101.325 kPa/atm

= 22.38 kPa

Option C is the correct answer

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

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