Which among the following ligands has highest field strength?

What is the number of moles of hydrogen atoms required to reduce one mole of nitroethane completely using Sn and HCl ?

Find the rate of following reaction.

$$ 2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \longrightarrow 4 \mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} $$

if concentration of $\mathrm{NO}_2$ increases to $5.2 \times 10^{-3} \mathrm{M}$ in 100 seconds.