Calculate the work done in following reaction at $27^{\circ} \mathrm{C}$.

$$ \begin{aligned} & 4 \mathrm{SO}_{2(\mathrm{~g})}+2 \mathrm{O}_{2(\mathrm{~g})} \longrightarrow 4 \mathrm{SO}_{3(\mathrm{~g})} \\ & \left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right) \end{aligned} $$

Which of the following principal of green chemistry suggest use of chemicals made from plant based sources?

Which from following cations will form most stable complex with same ligand?

Which is NOT correct regarding stock notation?