For the $1^{st}$ law of thermodynamics,select the correct option.

If $\Delta H$ is the change in enthalpy and $\Delta E$ is the change in internal energy accompanying a gaseous reaction,which of the following is true?

$A$ sample of liquid in a thermally insulated container (a calorimeter) is stirred for $2 \ hr$ by a mechanical linkage to a motor in the surroundings. For this process:

Based on the first law of thermodynamics,which of the following is correct?

For which of the following processes is $q = \Delta U$?

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 $R = 8.314 \, J \, mol^{-1} \, K^{-1}\left.\right]$