Thermodynamics Question 322
Question: P-V plots for two gases during adiabatic process are shown in figure. Plots 1 and 2 should correspond, respectively, to
Options:
A) He and $ O _{2} $
B) $ O _{2} $ and He
C) He and Ar
D) $ O _{2} $ and $ N _{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
[b]Slope of adiabatic curve $ \propto \gamma $
$ \propto \frac{1}{\text{Atomicity}\text{of}\text{the}\text{gas}} $ .
So, $ \gamma $ is inversely proportional to atomicity of the gas.
[as $ \gamma =1.66 $ for monoatomic gas, $ \gamma =1.4 $ for diatomic gas, and $ \gamma =1.33 $ for triatomic non-linear gas.]
From the graph it is clear that slope of curve 1 is less, so this should be adiabatic curve for diatomic gas (i.e., $ O _{2} $ ).
Similarly, slope of curve 2 is more, so it should be adiabatic curve for monoatomic gas (i.e. He).
