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?

For a reaction,$A_{(g)} \to A_{(l)}$; $\Delta H = -3RT$. The correct statement for the reaction is

At a certain temperature, $T(K)$, during a process, $500 \text{ J}$ is absorbed by the system and work of $200 \text{ J}$ is done by the system. Then the change in internal energy of the system is: (in $\text{ J}$)

For the reaction $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$,the relationship between $\Delta H$ and $\Delta U$ is:

Calculate the final volume when $2$ moles of an ideal gas expand from $3 \ dm^3$ at constant external pressure $1.6 \ bar$ and the work done in the process is $800 \ J$. (in $dm^3$)

$A$ mixture of gas expands from $0.03\, m^3$ to $0.06\, m^3$ at a constant pressure of $1\, MPa$ and absorbs $84\, kJ$ of heat during the process. The change in internal energy of the mixture is $.....\, kJ$.