Question

An ideal gas in thermally insulated vessel at internal pressure $=P_1$. volume $=V_1$ and absolute temperature $=T_1$ expands irrversibly against zero external pressure. as shown in the diagram. The final internal pressure, volume and absolute temperature of the gas are $P_2,V_2$ and $T_2$ respectively. for this expansion.

• A. $q=0$
• B. $T_2=T_1$
• C. $P_2{V}_2=P_1{V}_1$
• D. $P_2{V}_2^{\gamma }=P_1{V}_1^{\gamma }$

Answer 1

Answer: (A), (B), (C)

The correct options are
A $q=0$
B $T_2=T_1$
C $P_2{V}_2=P_1{V}_1$

Since the vessel is thermally insulated hence, $q=0$
Work done $w=0$ is zero for free expansion .
$\Delta U$ is also zero for free expansion , so $T_1=T_2$,and
$PV=$ constant ( isothermal process )