For the reaction $C_3H_8(g) + 5O_2(g) \rightarrow 3CO_2(g) + 4H_2O(l)$,the value of $\Delta H - \Delta U$ is:

$A$ gas undergoes a change from state $A$ to state $B$. In this process,the heat absorbed and work done by the gas are $5\, J$ and $8\, J$,respectively. Now,the gas is brought back to $A$ by another process during which $3\, J$ of heat is evolved. In this reverse process of $B$ to $A$:

Five moles of an ideal gas at $293 \, K$ is expanded isothermally from an initial pressure of $2.1 \, MPa$ to $1.3 \, MPa$ against a constant external pressure of $4.3 \, MPa$. The heat transferred in this process is $...... \, kJ \, mol^{-1}$. (Rounded-off to the nearest integer) $\left[\right.$ Use $R = 8.314 \, J \, mol^{-1} \, K^{-1}\left.\right]$

In a closed insulated container,a liquid is stirred with a paddle to increase its temperature. In this process,which of the following is true?

For which of the following reactions is $\Delta H \neq \Delta U$?

The work done by the system is $8 \, J$. When $40 \, J$ of heat is supplied to the system,the change in internal energy of the system during the process is ...... $J$.