Which among the following gases is adsorbed to greater extent at similar conditions of temperature and pressure if the adsorbent remains same?

What is the rate of disappearance of B in following reaction? $$2 \mathrm{A}+\mathrm{B} \rightarrow 3 \mathrm{C}$$, if rate of appearance of $$\mathrm{C}$$ is $$1.3 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$.

Which reagent oxidizes glucose to saccharic acid?

Two moles of an ideal gas are expanded isothermally from $$15 \mathrm{dm}^3$$ to $$20 \mathrm{dm}^3$$. If the amount of work done is $$-6 \mathrm{dm}^{-3}$$ bar, find external pressure needed to obtain this work.