Adiabatic Process: Final Temp & Heat Absorbed Calculation

[jimbo71]

Homework Statement

twenty moles of a monatomic ideal gas (lambda=5/3) undergo an adiabatic process the initial pressure is 400kpa and the initial temperature is 450K. The final temperature of the gas is 320K.
The heat absorbed by the gas in kJ is closest to?
a.0
b.+54
c.+32
d.-54
e.-32

Homework Equations

Q=0

The Attempt at a Solution

I think this is suppose to be a trick question. I thought an adiabatic process ment zero heat was gained or lost. Therefore shouldn't the answer be zero regardless of the temperature, moles, or pressure values given?

 

[LowlyPion]

An adiabatic process won't add or take heat away from a gas. It doesn't mean that the gas itself cannot change temperature as a result of say an increase in pressure. Since the question asks how much was absorbed and they have indicated it is adiabatic, then ... 0 looks to be the answer.

 

[thomate1]

I would agree with your reasoning. An adiabatic process is defined as one in which there is no exchange of heat between the system and its surroundings. This means that the heat absorbed by the gas in this process would be equal to zero, regardless of the initial and final temperatures, pressure, or number of moles. Therefore, the correct answer to this question would be option a. 0. It is important to always carefully consider the definitions and principles of a particular process before attempting to solve a problem.