If $3 \ mol$ of an ideal gas at $300 \ K$ expand isothermally from $30 \ dm^3$ to $45 \ dm^3$ against a constant opposing pressure of $80 \ kPa$,then the amount of heat transferred is . . . . . . $J$.

$A$ system does $394 \ J$ of work on the surroundings by absorbing $701 \ J$ of heat. What is the change in internal energy of the system (in $J$)?

$2 \ mol$ of an ideal gas are expanded isothermally and reversibly from $20 \ L$ to $40 \ L$ at $300 \ K$. Calculate work done. $(R=8.314 \ J \ K^{-1} \ mol^{-1})$ (in $J$)

An ideal gas,$\overline{C}_{V} = \frac{5}{2} R$,is expanded adiabatically against a constant pressure of $1 \ atm$ until it doubles in volume. If the initial temperature and pressure are $298 \ K$ and $5 \ atm$,respectively,then the final temperature is . . . . . . $K$ (nearest integer). [$\overline{C}_{V}$ is the molar heat capacity at constant volume]

During compression of a spring,the work done is $10 \ kJ$ and $2 \ kJ$ escaped to the surroundings as heat. The change in internal energy,$\Delta U$ (in $kJ$),is

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