An ideal gas expands from an initial volume of $5 \text{ dm}^3$ to $15 \text{ dm}^3$ against a constant external pressure of $2 \text{ atm}$. What is the work done by the gas (in $\text{ J}$)?

$A$ process has $\Delta H = 200 \ J \ mol^{-1}$ and $\Delta S = 40 \ J \ K^{-1} \ mol^{-1}$. Choose the minimum temperature above which the process will be spontaneous.

The standard entropy change for the reaction $4 Fe ( s ) + 3 O_{2} ( g ) \rightarrow 2 Fe_{2} O_{3} ( s )$ is $-550 \ J K^{-1}$ at $298 \ K$. Given: The standard enthalpy change for the reaction is $-165 \ kJ \ mol^{-1}$. The temperature in $K$ at which the reaction attains equilibrium is ... . (Nearest Integer)

$A$ spontaneous process is impossible if ........

For the reaction $A \to B$,$\Delta H = 4 \, kcal \, mol^{-1}$ and $\Delta S = 10 \, cal \, K^{-1} \, mol^{-1}$. At what temperature $(K)$ will the reaction become spontaneous?

Calculate $\Delta H_f^o$ for $UBr_4$ from the $\Delta G^o$ of reaction and the $S^o$ values: $U_{(s)} + 2Br_2(\ell) \to UBr_{4(s)}$; $\Delta G^o = -788.6 \ kJ$; $S^o \ (J/K \cdot mol): U_{(s)} = 50.3, Br_2(\ell) = 152.3, UBr_{4(s)} = 242.6$.