Question

An ideal gas is at pressure $P$ and temperature $T$ in a box, which is kept in vacuum within a large container. The wall of the box is punctured. What happens as the gas occupies all entire container?

• A. Its temperature falls
• B. Its temperature rises
• C. Its temperature remains the same
• D. Unpredictable

Answer 1

Answer: (C)

Its temperature remains the same

This is a case of free expansion of gas,

Free expansion-Always going to be irrerversible and since $P_{ext}=0$

so $dW=-Pext.dV=0$

If no. heat is supplied $q=0$

then $\Delta E=0$ so $\Delta T=0$.

Temperature is constant.

$\therefore$ option C is correct.