For a gaseous reaction,$A_{(g)} + 3B_{(g)} \to 3C_{(g)} + 3D_{(g)}$. The value of $\Delta E$ is $17 \ kcal$ at $27 \ ^oC$. The value of $\Delta H$ in $kcal$ will be:

When a system is supplied with $60 \ J$ of heat,it performs $15 \ J$ of work. The change in the internal energy of the system is ......... $J$.

Consider the same expansion,but this time against a constant external pressure of $1 \ atm$.

If $2 \ kJ$ of heat is released from the system and $6 \ kJ$ of work is done on the system,what is the internal energy change $(\Delta U)$ of the system?

At $300 \ K$,the enthalpy change for the reaction $C_3H_8(g) + 5O_2(g) \rightarrow 3CO_2(g) + 4H_2O(l)$ is $-2800 \ kJ \ mol^{-1}$. Calculate the internal energy change $(\Delta U)$ for the reaction at the same temperature.

$A$ 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 $J$)