Question

Which of the following is the correct option for free expansion of an ideal gas under adiabatic condition?

• A. $q=0, \Delta T\ne0, W=0$
• B. $q=0, \Delta T\ne0, W\ne0$
• C. $q=0, \Delta T=0, W=0$
• D. $q=0, \Delta T=0, W\ne0$

Answer 1

Answer: (C)

$q=0, \Delta T=0, W=0$

Answer 2

For the free expansion of an ideal gas, the opposing force is zero, hence work done = 0.
$\Delta U=q+w, w=0, hence \Delta U=q$
But the process is adiabatic, hence q = 0
$\therefore q=0, \Delta T=0, W=0$