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 . . . . . . $J$.

Calculate $\Delta H$ for the following reaction at $300 \text{ K}$: $2C(s) + 3H_2(g) \rightarrow C_2H_6(g)$ if $\Delta U$ for the reaction is $-80 \text{ kJ}$ $(R = 8.314 \text{ J K}^{-1} \text{mol}^{-1})$ (in $\text{ kJ}$)

$A$ system receives $100 \ cal$ of heat,and at the same time,$50 \ cal$ of work is done by the system. Calculate the change in internal energy. (in $cal$)

$A$ gas absorbs $100 \ J$ of heat and is simultaneously compressed by a constant external pressure of $1.5 \ atm$ from a volume of $8.0 \ L$ to $2.0 \ L$. The change in internal energy for the gas in Joules is $(1 \ L \cdot atm = 101.32 \ J)$.

Joule-Thomson expansion is:

The work done in ergs for the reversible expansion of one mole of an ideal gas from a volume of $10 \ L$ to $20 \ L$ at $25 \, ^oC$ is