$A$ gas present in a cylinder expands against a constant pressure of $1 \, atm$ from a volume of $2 \, L$ to a volume of $6 \, L$. In doing so,it absorbs $800 \, J$ of heat from the surroundings. The change in internal energy of the process is ....... $J$.

Identify the correct statements from the following:
$I$. $\Delta_{r} G$ is zero for $A \rightleftharpoons B$ reaction.
$II$. The entropy of pure crystalline solids approaches zero as the temperature approaches absolute zero.
$III$. $\Delta U$ of a reaction can be determined using a bomb calorimeter.

The $\Delta E^o$ of combustion of $2-$methylpropene is $-X \ kJ \ mol^{-1}$. The value of $\Delta H^o$ is

When $1 \ g$ of $NH_4NO_3$ is decomposed in a bomb calorimeter,the temperature of the calorimeter increases by $6.12 \ K$. If the heat capacity of the system is $1.23 \ kJ/K$,the molar enthalpy of decomposition of $NH_4NO_3$ is ........ $kJ/mol$.

When $1.0 \ g$ of solid oxalic acid $(H_2C_2O_4)$ is burned in a bomb calorimeter whose heat capacity is $8.75 \ kJ/K$,the temperature increases by $0.312 \ K$. The enthalpy of combustion of oxalic acid at $27 \ ^oC$ is

For the process $H_2O_{(l)} \rightarrow H_2O_{(g)}$ at $100^{\circ}C$ and $1 \ atm$ pressure,which of the following is true?