During the free expansion of an ideal gas in an isolated chamber,

$A$ gas undergoes a change from state $A$ to state $B$. In this process,the heat absorbed and work done by the gas are $5\, J$ and $8\, J$,respectively. Now,the gas is brought back to $A$ by another process during which $3\, J$ of heat is evolved. In this reverse process of $B$ to $A$:

“The mass and energy both are conserved in an isolated system”,is the statement of

$A$ mixture of gas expands from $0.03\, m^3$ to $0.06\, m^3$ at a constant pressure of $1\, MPa$ and absorbs $84\, kJ$ of heat during the process. The change in internal energy of the mixture is $.....\, kJ$.

An isolated chamber is divided into two halves by a partition,with an ideal gas in one half. By making a hole in the partition,the gas is allowed to expand to the full chamber. Among the following,the parameter which changes in the process is

Which one of the following is applicable for an adiabatic expansion of an ideal gas?