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.

The rate constant of a first order reaction is $1.15 \times 10^{-3} \mathrm{~s}^{-1}$. How long will 5 g of reactant take to reduce to 3 g ?

Which of the following is an example of first order reaction?

For a reaction,

$\mathrm{A}+\mathrm{B} \longrightarrow$ product, it is found that rate law is $\mathrm{r}=\mathrm{k}[\mathrm{A}]^{1.5}[\mathrm{~B}]^{2.5}$. What is the order of reaction?