Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be .............. $Joules$.

$2 \ \text{moles}$ of a gas undergoes a change in state from $(2 \ \text{bar}, 40 \ \text{L})$ to $(5 \ \text{bar}, 15 \ \text{L})$ at a constant temperature. If the change in internal energy is given by $35 \ \text{bar-L}$, then the enthalpy change for the process will be: (in $\text{bar-L}$)

Which of the following compounds is $NOT$ present in its standard state at $25^{\circ} C$ and $1 \text{ atmosphere}$ pressure?

For a chemical reaction,when does $\Delta H = \Delta U$ occur?

$5 \ mol$ of an ideal monoatomic gas is compressed isothermally from $(40 \ L, 5 \ bar)$ to $4 \ L$. The magnitude of maximum work done on the gas in this compression is

The magnitude of work done by a gas that undergoes a reversible expansion along the path $ABC$ shown in the figure is .............. $Joule$.