Solution Found!
FIGURE shows a thermodynamic process followed by 120 mg of
Chapter 17, Problem 77CP(choose chapter or problem)
Figure CP17.77 shows a thermodynamic process followed by \(120 \mathrm{mg}\) of helium.
a. Determine the pressure (in atm), temperature (in \(\left.{ }^{\circ} \mathrm{C}\right)\), and volume (in \(\mathrm{cm}^{3}\) ) of the gas at points 1,2 , and 3 . Put your results in a table for easy reading.
Equation Transcription:
Text Transcription:
120 mg
^circC
cm^3
Questions & Answers
QUESTION:
Figure CP17.77 shows a thermodynamic process followed by \(120 \mathrm{mg}\) of helium.
a. Determine the pressure (in atm), temperature (in \(\left.{ }^{\circ} \mathrm{C}\right)\), and volume (in \(\mathrm{cm}^{3}\) ) of the gas at points 1,2 , and 3 . Put your results in a table for easy reading.
Equation Transcription:
Text Transcription:
120 mg
^circC
cm^3
ANSWER:
Step 1 of 3
Part a
We are required to calculate the pressure, temperature and volume at the given points 1,2 and 3.
At the point 1, the pressure is 3 atm. The volume is 1000 .
Pressure atm Pa
Volume = 0.001
The mass of helium is mg = 120 g
The molar mass of helium is 4.0 g.
Therefore, the number of moles of helium is = 30 = 0.03 mole
Therefore, the temperature of helium at the point 1 is,
K
K
°C
°C
Therefore, at the point 1,
3.0 atm |
1000 |
942 °C |
The system reaches point 2 after an isothermal expansion.
At this point, the volume is = 0.003
The temperature is 942 °C as the process is isothermal.
The process is isothermal and the volume increases by three times. So, the pressure at this point will be reduced by three times. So, the pressure at the point 2 is 1 atm.
Therefore, at the point 2,
1.0 atm |
3000 |
942 °C |
The system reaches point 3 at constant volume. This is followed by an adiabatic compression to state 1. Helium has .
Therefore, to calculate the pressure the point 3, we have to consider the following equation,
atm
atm
Therefore, the pressure at the point 3 is 0.48 atm.
For an adiabatic process, the temperature of the point 3 can be calculated from the following equation,
K
K
K
°C
°C
Therefore, the temperature at the point 3 is 310 °C.
Therefore, at the point 3,
0.48 atm |
3000 |
310 °C |