If $100 \ L$ of gas is enclosed in a cylinder, absorbs $302.6 \ J$ of heat and expands to $200 \ L$ against a constant external pressure of $2 \ Pa$, calculate the internal energy change of the gas. (in $J$)

The conservation of mass and energy is demonstrated by:

Calculate the change in internal energy of the system if $20 \ kJ$ of work is done on the system and it releases $10 \ kJ$ of heat in a particular reaction. (in $kJ$)

$A$ gas expands against a variable pressure given by $P = \frac{20}{V}$ ($P$ in $atm$ and $V$ in $L$). During expansion from volume of $1 \ L$ to $10 \ L$,the gas undergoes an increase in internal energy of $400 \ J$. How much heat is absorbed by gas during expansion (in $J$)? (Given: $1 \ L \cdot atm = 101.3 \ J$)

$A$ 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 $A$:

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