Question

The correct option for free expansion of an ideal gas under adiabatic condition is:

• A. $q<0,\Delta T=0\text{and}w=0$
• B. $q>0,\Delta T>0\text{and}w>0$
• C. $q=0,\Delta T=0\text{and}w=0$
• D. $q=0,\Delta T<0\text{and}w>0$

Answer 1

The correct option is C $q=0,\Delta T=0\text{and}w=0$

For an adiabatic process, $q=0$
For free expansion, $P_{ext}=0$
$\therefore w=0$
and from first law of thermodynamics:
$\Delta E=0\text{or}\Delta T=0$