The $\Delta U^o$ of combustion of $CH_{4(g)}$ at a certain temperature is $-393 \ kJ/mol$. Then the value of $\Delta H^o$ is:

The first law of thermodynamics for an isothermal process is:

$q$ and $w$ are both ....... functions and $q + w$ is a ....... function.

Two vessels $A$ and $B$ are connected via a stopcock. Vessel $A$ is filled with a gas at a certain pressure. The entire assembly is immersed in water and allowed to reach thermal equilibrium. After opening the stopcock,the gas from vessel $A$ expands into vessel $B$,and no change in temperature is observed. Which of the following statements is true?

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

What is the change in internal energy of the system when the work done by the system is $150 \ J$ and the system releases $300 \ J$ of heat?