Calculate the work done for the following reaction at $27\,^\circ\text{C}$
$\text{C}_2\text{H}_{4(g)} + \text{H}_{2(g)} \longrightarrow \text{C}_2\text{H}_{6(g)}$ ($R = 8.314\,\text{JK}^{-1}\text{mol}^{-1}$)

Which from following is NOT a state function ?

Calculate the $[\text{H}_3\text{O}^+]$ if pH of the solution is $4.25$

If $[\text{H}_3\text{O}^+]$ of a solution is $1 \times 10^{-4}$. What is the value of pOH at $298\,\text{K}$ ?