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.

Identify correct statement for reaction stated below.

$$ \mathrm{Ag}_2 \mathrm{O}+\mathrm{H}_2 \mathrm{O}+2 \mathrm{e}^{-} \longrightarrow 2 \mathrm{Ag}+2 \mathrm{OH}^{-} $$

Which of the following inert gases is used for magnetic resonance imaging?

A weak base is $5 \%$ dissociated in its 0.01 M solution. Calculate the dissociation constant.