A piston contains 710 moles of an ideal monatomic gas that initally has a pressu

Question

A piston contains 710 moles of an ideal monatomic gas that initally has a pressure of 1.44 × 105 Pa and a volume of 3.4 m3. The piston is connected to a hot and cold reservoir and the gas goes through the following quasi-static cycle accepting energy from the hot reservoir and exhausting energy into the cold reservoir.

The pressure of the gas is increased to 4.44 × 105 Pa while maintaining a constant volume.

The volume of the gas is increased to 10.4 m3 while maintaining a constant pressure.

The pressure of the gas is decreased to 1.44 × 105 Pa while maintaining a constant volume.

The volume of the gas is decreased to 3.4 m3 while maintaining a constant pressure.

It may help you to recall that CVCV = 12.47 J/K/mole and CPCP = 20.79 J/K/mole for a monatomic ideal gas, and that the number of gas molecules is equal to Avagadros number (6.022 × 1023) times the number of moles of the gas.

1)

How much energy is transferred into the gas from the hot reservoir?

2)

How much energy is transferred out of the gas into the cold reservoir?

3)

How much work is done by the gas?

4)

What is the efficiency of this cycle?

Explanation / Answer

1)
Q=L
Q=pV=nRTln(V2/V1)

2)
Q=-U
Q=-3/2nRT

3)
L=-nRT(V2/V1)=nRT(V1/V2)

4)Eff = 1 - QH/QC

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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