Question

For an ideal gas, consider only P-V work in going from an initial state X to the final state Z. The final state Z can be reached by either of the two paths shown in the figure. Which of the following choices is (are) correct?
[Take $△$S as change in entropy and w as work done].

• A. $△S_{x\to z}=△S_{x\to y}+△S_{y\to z}$
• B. $W_{x\to z}=W_{x\to y}+W_{y\to z}$
• C. $W_{x\to y\to z}=W_{x\to y}$
• D. $△S_{x\to y\to z}=△S_{x\to y}$

Answer 1

Answer: (A), (C)

The correct options are
A $△S_{x\to z}=△S_{x\to y}+△S_{y\to z}$
C $W_{x\to y\to z}=W_{x\to y}$


$\left(a\right)△S_{x\to y}=△S_{y\to z}+△S_{y\to z}\left(Correct\right)$ (It is state function)
$\left(b\right)W_{x\to z}=W_{x\to y}+W_{y\to z}\left(Incorrect\right)$ (Not a state function)
$\left(c\right)W_{x\to y\to z}=W_{x\to y}\left(Correct\right)$ (It is state function)
$\left(d\right)△S_{x\to y\to z}=△S_{x\to y}$ (Incorrect)