Finding Gas Mass Using Heat Exchange at Constant Pressure and Volume

In summary, the problem involves an ideal gas with a mass of 28kg/mole and an initial temperature that increases by 14K when 29J of heat is added at a constant pressure. To cool the gas back to its initial temperature, 20.7J of heat is extracted at a constant volume. The task is to find the mass of the gas. To solve this, the 1st law is used to determine the number of moles (n) as a function of the heat capacity at constant volume (CV). Then, the mass can be calculated by multiplying the number of moles by 28kg.
  • #1
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Homework Statement


The temperature of an ideal gas (M=28kg/mole) has increased 14K by adding 29J of heat at a constant pressure. To cool the gas back to the initaial temperature 20.7J of heat is extracted from the gas at a constant volume. Find the mass of the gas.


Homework Equations


ΔU=(3/2)nRΔT
n=number of moles
R=8.31
T=temperature

The Attempt at a Solution


none
 
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  • #2
1. ΔT = +14K, Q = 29J: can you use the 1st law to determine the number of moles n as a function of CV, the heat capacity at constant volume?

2. ΔT = -14K, Q = -20.9J: can you use the 1st law again to determine CV?
Then you'd have n and of course m = 28kg*n.
 

Related to Finding Gas Mass Using Heat Exchange at Constant Pressure and Volume

1. What are the gas laws?

The gas laws are a set of fundamental principles that describe the behavior of gases. They include Boyle's law, Charles's law, Gay-Lussac's law, and Avogadro's law.

2. What is Boyle's law?

Boyle's law states that at a constant temperature, the pressure and volume of a gas are inversely proportional. This means that as the pressure on a gas decreases, its volume increases, and vice versa.

3. How does Charles's law relate to gas behavior?

Charles's law states that at a constant pressure, the volume of a gas is directly proportional to its absolute temperature. This means that as the temperature of a gas increases, its volume also increases, and vice versa.

4. What is the kinetic theory of gases?

The kinetic theory of gases explains the behavior of gases in terms of the motion of their particles. It states that gas particles are in constant, random motion and that their kinetic energy is directly proportional to their temperature.

5. How does the ideal gas law relate to the kinetic theory?

The ideal gas law, PV = nRT, combines the gas laws and the kinetic theory into one equation. It describes the relationship between pressure, volume, temperature, and the number of moles of an ideal gas. It is based on the assumptions that gas particles have no volume and do not interact with each other.

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