$A$ sample of gas absorbs $4000 \ kJ$ of heat and the surrounding does $2000 \ J$ of work on the sample. What is the value of $\Delta U$ (in $kJ$)?

$A$ system does $200 \, J$ of work and at the same time absorbs $150 \, J$ of heat. The magnitude of the change in internal energy is $..... \, J.$ (Nearest integer)

Assertion : For a reaction $2NH_{3(g)} \to N_{2(g)} + 3H_{2(g)}$ ; $\Delta H > \Delta E$.
Reason : Enthalpy change is always greater than internal energy change.

$A$ piston filled with $0.04\, mol$ of an ideal gas expands reversibly from $50.0\, mL$ to $375\, mL$ at a constant temperature of $37\, ^oC$. It absorbs $208\, J$ of heat in this process. The value of $q$ and $w$ for the process will be: $(R = 8.314\, J / mol\, K)$ $(\ln 7.5 = 2.01)$

For the reaction,$N_{2(g)} + 3 H_{2(g)} \rightarrow 2 NH_{3(g)}$,$\Delta H$ is equal to

$A$ gas expands isothermally from $10 \, dm^3$ to $20 \, dm^3$ at a constant external pressure of $1 \, atm$. If it absorbs $800 \, J$ of heat from the surroundings,what is the value of $\Delta U$ in $J$ for this process?