Isothermal compression of monatomic gas ?

In summary, a forum member is seeking help with a homework problem involving an isothermal compression of a monoatomic ideal gas. They mention the initial volume and pressure as well as the total energy and conservation of internal energy. However, another member simplifies the problem by using the equation of an ideal gas and solving for the final pressure. There is a brief discussion about whether or not to provide a complete solution.
  • #1
zaf
Hello forum members

I need some help on H.W problem...just enough reasoning to atleast get started

the question is as follows:
5 moles of a monoatomic ideal gas at an initial volume of .50 m^3 and an initial pressure of 2.0 * 10^5 Pa undergoes an isothermal compression to .20m^3. Find the final pressure ?

so, the temperature is going to be constant , the inital and final volumes and intial pressure is also know, also the total energy (Q)is going to be work done on the gas... which must be negaive... internal energy is conserved ? am i correct so far...how do i solve this ?
 
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  • #2
You're overcomplicating. The energy doesn't figure into it. It is also irrelevant that the gas is monatomic. The problem is much easier than you suspect.


Njorl
 
  • #3
Right Njorl,
all there is to use is the equation of an ideal gas:
pV = nRT.
Since there is initial & final state, it's a system of 2 equations:
I) p1V1 = nRT
II) p2V2 = nRT
Now, T is not given, so you better eliminate it:
I) T = p1V1/nR
II) T = p2V2/nR
Which are clearly equal, so
I = II) p1V1/nR = p2V2/nR
or (nR cancels)
p1V1 = p2V2
And we solve for p2:
p2= p1V1/V2
OK?
 
  • #4
Yes, but I thought it should be left for Zaf to do with just the hint.

Njorl
 
  • #5
yes. i understand arcnets... thank you
 
  • #6
Originally posted by Njorl
Yes, but I thought it should be left for Zaf to do with just the hint.

Njorl
Yes, right. Maybe that was a little too much...
 

1. What is isothermal compression of monatomic gas?

Isothermal compression of monatomic gas is a process in which a monatomic gas is compressed while maintaining a constant temperature. This means that the pressure and volume of the gas change, but the temperature remains the same.

2. How is isothermal compression different from adiabatic compression?

Isothermal compression and adiabatic compression are two different processes that involve compressing a gas. The main difference between them is that isothermal compression keeps the temperature constant, while adiabatic compression does not allow for any heat transfer, resulting in a change in temperature.

3. What is the ideal gas law and how is it related to isothermal compression?

The ideal gas law is a mathematical equation that describes the relationship between the pressure, volume, and temperature of an ideal gas. In the case of isothermal compression, the ideal gas law is used to calculate the change in pressure and volume of the gas while keeping the temperature constant.

4. What is the purpose of isothermal compression in scientific experiments?

Isothermal compression is often used in scientific experiments to study the behavior of gases under different conditions. It can also be used to compress gases to high pressures without changing their temperature, which is important in industrial processes such as gas storage and transportation.

5. How does isothermal compression affect the internal energy of a gas?

During isothermal compression, the internal energy of a gas remains constant since the temperature is not changing. This means that the work done on the gas during compression is equal to the heat released by the gas, resulting in no change in internal energy. However, the pressure and volume of the gas do change, which can affect other properties such as density and molar heat capacity.

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