Question

Calculate the max. work done by system in an irreversible (single step) adiabatic expression of 1 mole of a polyatomic gas from 300K pressure 10 atm to 1 atm.($\gamma$ = 1.33)

Answer 1

According to the problem:

Let us consider the work done for adiabatic irreversible expansion

$w=n{C}_v\left(T_2-T_1\right)$

for $T_2$

$\left(\frac{T_2}{T_1}\right)={\left(\frac{P_2}{P_1}\right)}^{\left[1-\frac{1}{\gamma }\right]}$

implies that

$T_2=T\times {\left(\frac{1}{10}\right)}^{\left[1-\frac{1}{1.33}\right]}$

$=300\times 1.175$

$=525K$

To find cv:

$\gamma -1=\frac{R}{CV}$

or

$Cv=\frac{8.314}{1.33-1}$

$=25.19$

substitute in equation,

$w=5.5KJmo{l}^{-1}$