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

For the reversible isothermal expansion of $1 \, \text{mol}$ of an ideal gas at $300 \, K$ from a volume of $10 \, dm^3$ to $20 \, dm^3$,the value of $\Delta H$ in $kJ$ is:

Calculate work done in isothermal reversible expansion of $1 \ mol$ of an ideal gas from an initial pressure of $10 \ bar$ to a final pressure of $1 \ bar$ at $300 \ K$ $\left(R = 8.314 \ J \ K^{-1} \ mol^{-1}\right)$. (in $kJ$)

Calculate the work done when $2$ moles of an ideal gas expand from a volume of $5 \ dm^3$ to $7 \times 10^{-3} \ m^3$ against a constant external pressure of $2.02 \times 10^5 \ Nm^{-2}$. (in $kJ$)

When $2$ moles of an ideal gas are expanded isothermally from a volume of $12.5 \ L$ to $15.0 \ L$ against a constant external pressure of $760 \ mm \ Hg$,calculate the amount of work done in joules. (in $J$)

For the reaction,$A_{(s)} + 3B_{(g)} \to 4C_{(s)} + D_{(l)}$,$\Delta H$ and $\Delta U$ are related as $\dots$