The law of conservation of energy states that

An ideal gas expands adiabatically against vacuum. Which of the following is correct for the given process?

$A$ gas performs $0.320 \ kJ$ work on the surrounding and absorbs $120 \ J$ of heat from the surrounding. Hence,the change in internal energy is: (in $J$)

$A$ sample of liquid in a thermally insulated container (a calorimeter) is stirred for $2 \ hr$ by a mechanical linkage to a motor in the surroundings. For this process:

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

One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27\,^{\circ}C$. If the work done during the process is $3\, kJ$,then the final temperature of the gas is $(C_v = 20\, J/K)$ .....$K$